diff --git a/.travis.yml b/.travis.yml
index 732ace6..36ca0da 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -89,6 +89,25 @@ matrix:
     - name: '[INFECTION] PHP Nightly With Highest Dependencies'
       php: nightly
       env: infection=1 dependencies=highest
+
+    - name: '[PHPSTAN] PHP 7.3 With Locked Dependencies'
+      php: '7.3'
+      env: phpstan=1
+    - name: '[PHPSTAN] PHP 7.3 With Lowest Dependencies'
+      php: '7.3'
+      env: phpstan=1 dependencies=lowest
+    - name: '[PHPSTAN] PHP 7.3 With Highest Dependencies'
+      php: '7.3'
+      env: phpstan=1 dependencies=highest
+    - name: '[PHPSTAN] PHP Nightly With Locked Dependencies'
+      php: nightly
+      env: phpstan=1
+    - name: '[PHPSTAN] PHP Nightly With Lowest Dependencies'
+      php: nightly
+      env: phpstan=1 dependencies=lowest
+    - name: '[PHPSTAN] PHP Nightly With Highest Dependencies'
+      php: nightly
+      env: phpstan=1 dependencies=highest
   allow_failures:
     - name: '[CS] PHP Nightly With Locked Dependencies'
       php: nightly
@@ -129,6 +148,16 @@ matrix:
     - name: '[INFECTION] PHP Nightly With Highest Dependencies'
       php: nightly
       env: infection=1 dependencies=highest
+
+    - name: '[PHPSTAN] PHP Nightly With Locked Dependencies'
+      php: nightly
+      env: phpstan=1
+    - name: '[PHPSTAN] PHP Nightly With Lowest Dependencies'
+      php: nightly
+      env: phpstan=1 dependencies=lowest
+    - name: '[PHPSTAN] PHP Nightly With Highest Dependencies'
+      php: nightly
+      env: phpstan=1 dependencies=highest
 services:
   - redis-server
 
@@ -144,11 +173,11 @@ before_script:
   - if [ -z "$dependencies" ]; then travis_retry composer install -n; fi;
   - if [ "$dependencies" = "lowest" ]; then travis_retry composer update --prefer-lowest -n; fi;
   - if [ "$dependencies" = "highest" ]; then travis_retry composer update -n; fi;
-  - wget https://github.com/infection/infection/releases/download/0.12.2/infection.phar
-  - wget https://github.com/infection/infection/releases/download/0.12.2/infection.phar.asc
-  - gpg --keyserver hkps.pool.sks-keyservers.net --recv-keys 493B4AA0
-  - gpg --with-fingerprint --verify infection.phar.asc infection.phar
-  - chmod +x infection.phar
+  - if [ "$infection" = 1 ]; then wget https://github.com/infection/infection/releases/download/0.12.2/infection.phar; fi;
+  - if [ "$infection" = 1 ]; then wget https://github.com/infection/infection/releases/download/0.12.2/infection.phar.asc; fi;
+  - if [ "$infection" = 1 ]; then gpg --keyserver hkps.pool.sks-keyservers.net --recv-keys 493B4AA0; fi;
+  - if [ "$infection" = 1 ]; then gpg --with-fingerprint --verify infection.phar.asc infection.phar; fi;
+  - if [ "$infection" = 1 ]; then chmod +x infection.phar; fi;
 
 script:
   - if [ "$unit" = 1 ]; then phpdbg -qrr vendor/bin/phpunit --testsuite HarmonIOCacheUnitTestSuite --coverage-text --coverage-clover build/logs/clover.xml; fi;
@@ -156,6 +185,7 @@ script:
   - if [ "$cs" = 1 ]; then vendor/bin/phpcs -s; fi;
   - if [ "$require" = 1 ]; then vendor/bin/composer-require-checker check; fi;
   - if [ "$infection" = 1 ]; then phpdbg -qrr ./infection.phar --min-msi=100 --min-covered-msi=100 --threads=4 --show-mutations; fi;
+  - if [ "$phpstan" = 1 ]; then vendor/bin/phpstan analyse src --level max; fi;
 
 after_success:
   - if [ "$unit" = 1 ]; then travis_retry php php-coveralls.phar; fi;
diff --git a/appveyor.yml b/appveyor.yml
index 78b18bb..7fdf51e 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -30,6 +30,9 @@ init:
   - SET PHP=1
   - SET ANSICON=121x90 (121x90)
 install:
+  # Setup WSUS
+  - choco install chocolatey-windowsupdate.extension
+
   # Install Redis
   - nuget install redis-64 -excludeversion
   - redis-64\tools\redis-server.exe --service-install
diff --git a/composer.json b/composer.json
index c7b35b7..2fbd339 100644
--- a/composer.json
+++ b/composer.json
@@ -22,6 +22,7 @@
         "harmonyio/php-codesniffer-ruleset": "dev-master",
         "harmonyio/phpunit-extension": "dev-master",
         "maglnet/composer-require-checker": "^2.0.0",
+        "phpstan/phpstan": "^0.11.5",
         "phpunit/phpunit": "^8.1.3",
         "slevomat/coding-standard": "^5.0.4",
         "squizlabs/php_codesniffer": "^3.4.2"
diff --git a/composer.lock b/composer.lock
index 0a5a063..7ae32a0 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "83843d0a46e0fae66b1b7d9d79454cec",
+    "content-hash": "23403803673f34e2a2446049d0690d40",
     "packages": [
         {
             "name": "amphp/amp",
@@ -615,6 +615,50 @@
         }
     ],
     "packages-dev": [
+        {
+            "name": "composer/xdebug-handler",
+            "version": "1.3.2",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/composer/xdebug-handler.git",
+                "reference": "d17708133b6c276d6e42ef887a877866b909d892"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/composer/xdebug-handler/zipball/d17708133b6c276d6e42ef887a877866b909d892",
+                "reference": "d17708133b6c276d6e42ef887a877866b909d892",
+                "shasum": ""
+            },
+            "require": {
+                "php": "^5.3.2 || ^7.0",
+                "psr/log": "^1.0"
+            },
+            "require-dev": {
+                "phpunit/phpunit": "^4.8.35 || ^5.7 || ^6.5"
+            },
+            "type": "library",
+            "autoload": {
+                "psr-4": {
+                    "Composer\\XdebugHandler\\": "src"
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "John Stevenson",
+                    "email": "john-stevenson@blueyonder.co.uk"
+                }
+            ],
+            "description": "Restarts a process without xdebug.",
+            "keywords": [
+                "Xdebug",
+                "performance"
+            ],
+            "time": "2019-01-28T20:25:53+00:00"
+        },
         {
             "name": "doctrine/instantiator",
             "version": "1.2.0",
@@ -747,6 +791,57 @@
             "description": "Asynchronous helpers for PHPUnit",
             "time": "2019-04-29T06:27:08+00:00"
         },
+        {
+            "name": "jean85/pretty-package-versions",
+            "version": "1.2",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/Jean85/pretty-package-versions.git",
+                "reference": "75c7effcf3f77501d0e0caa75111aff4daa0dd48"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/Jean85/pretty-package-versions/zipball/75c7effcf3f77501d0e0caa75111aff4daa0dd48",
+                "reference": "75c7effcf3f77501d0e0caa75111aff4daa0dd48",
+                "shasum": ""
+            },
+            "require": {
+                "ocramius/package-versions": "^1.2.0",
+                "php": "^7.0"
+            },
+            "require-dev": {
+                "phpunit/phpunit": "^6.0"
+            },
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "1.x-dev"
+                }
+            },
+            "autoload": {
+                "psr-4": {
+                    "Jean85\\": "src/"
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Alessandro Lai",
+                    "email": "alessandro.lai85@gmail.com"
+                }
+            ],
+            "description": "A wrapper for ocramius/package-versions to get pretty versions strings",
+            "keywords": [
+                "composer",
+                "package",
+                "release",
+                "versions"
+            ],
+            "time": "2018-06-13T13:22:40+00:00"
+        },
         {
             "name": "maglnet/composer-require-checker",
             "version": "2.0.0",
@@ -865,6 +960,529 @@
             ],
             "time": "2019-04-07T13:18:21+00:00"
         },
+        {
+            "name": "nette/bootstrap",
+            "version": "v3.0.0",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/nette/bootstrap.git",
+                "reference": "e1075af05c211915e03e0c86542f3ba5433df4a3"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/nette/bootstrap/zipball/e1075af05c211915e03e0c86542f3ba5433df4a3",
+                "reference": "e1075af05c211915e03e0c86542f3ba5433df4a3",
+                "shasum": ""
+            },
+            "require": {
+                "nette/di": "^3.0",
+                "nette/utils": "^3.0",
+                "php": ">=7.1"
+            },
+            "require-dev": {
+                "latte/latte": "^2.2",
+                "nette/application": "^3.0",
+                "nette/caching": "^3.0",
+                "nette/database": "^3.0",
+                "nette/forms": "^3.0",
+                "nette/http": "^3.0",
+                "nette/mail": "^3.0",
+                "nette/robot-loader": "^3.0",
+                "nette/safe-stream": "^2.2",
+                "nette/security": "^3.0",
+                "nette/tester": "^2.0",
+                "tracy/tracy": "^2.6"
+            },
+            "suggest": {
+                "nette/robot-loader": "to use Configurator::createRobotLoader()",
+                "tracy/tracy": "to use Configurator::enableTracy()"
+            },
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "3.0-dev"
+                }
+            },
+            "autoload": {
+                "classmap": [
+                    "src/"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "BSD-3-Clause",
+                "GPL-2.0",
+                "GPL-3.0"
+            ],
+            "authors": [
+                {
+                    "name": "David Grudl",
+                    "homepage": "https://davidgrudl.com"
+                },
+                {
+                    "name": "Nette Community",
+                    "homepage": "https://nette.org/contributors"
+                }
+            ],
+            "description": "🅱 Nette Bootstrap: the simple way to configure and bootstrap your Nette application.",
+            "homepage": "https://nette.org",
+            "keywords": [
+                "bootstrapping",
+                "configurator",
+                "nette"
+            ],
+            "time": "2019-03-26T12:59:07+00:00"
+        },
+        {
+            "name": "nette/di",
+            "version": "v3.0.0",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/nette/di.git",
+                "reference": "19d83539245aaacb59470828919182411061841f"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/nette/di/zipball/19d83539245aaacb59470828919182411061841f",
+                "reference": "19d83539245aaacb59470828919182411061841f",
+                "shasum": ""
+            },
+            "require": {
+                "ext-tokenizer": "*",
+                "nette/neon": "^3.0",
+                "nette/php-generator": "^3.2.2",
+                "nette/robot-loader": "^3.2",
+                "nette/schema": "^1.0",
+                "nette/utils": "^3.0",
+                "php": ">=7.1"
+            },
+            "conflict": {
+                "nette/bootstrap": "<3.0"
+            },
+            "require-dev": {
+                "nette/tester": "^2.2",
+                "tracy/tracy": "^2.3"
+            },
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "3.0-dev"
+                }
+            },
+            "autoload": {
+                "classmap": [
+                    "src/"
+                ],
+                "files": [
+                    "src/compatibility.php"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "BSD-3-Clause",
+                "GPL-2.0",
+                "GPL-3.0"
+            ],
+            "authors": [
+                {
+                    "name": "David Grudl",
+                    "homepage": "https://davidgrudl.com"
+                },
+                {
+                    "name": "Nette Community",
+                    "homepage": "https://nette.org/contributors"
+                }
+            ],
+            "description": "💎 Nette Dependency Injection Container: Flexible, compiled and full-featured DIC with perfectly usable autowiring and support for all new PHP 7.1 features.",
+            "homepage": "https://nette.org",
+            "keywords": [
+                "compiled",
+                "di",
+                "dic",
+                "factory",
+                "ioc",
+                "nette",
+                "static"
+            ],
+            "time": "2019-04-03T19:35:46+00:00"
+        },
+        {
+            "name": "nette/finder",
+            "version": "v2.5.0",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/nette/finder.git",
+                "reference": "6be1b83ea68ac558aff189d640abe242e0306fe2"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/nette/finder/zipball/6be1b83ea68ac558aff189d640abe242e0306fe2",
+                "reference": "6be1b83ea68ac558aff189d640abe242e0306fe2",
+                "shasum": ""
+            },
+            "require": {
+                "nette/utils": "^2.4 || ~3.0.0",
+                "php": ">=7.1"
+            },
+            "conflict": {
+                "nette/nette": "<2.2"
+            },
+            "require-dev": {
+                "nette/tester": "^2.0",
+                "tracy/tracy": "^2.3"
+            },
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "2.5-dev"
+                }
+            },
+            "autoload": {
+                "classmap": [
+                    "src/"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "BSD-3-Clause",
+                "GPL-2.0",
+                "GPL-3.0"
+            ],
+            "authors": [
+                {
+                    "name": "David Grudl",
+                    "homepage": "https://davidgrudl.com"
+                },
+                {
+                    "name": "Nette Community",
+                    "homepage": "https://nette.org/contributors"
+                }
+            ],
+            "description": "? Nette Finder: find files and directories with an intuitive API.",
+            "homepage": "https://nette.org",
+            "keywords": [
+                "filesystem",
+                "glob",
+                "iterator",
+                "nette"
+            ],
+            "time": "2019-02-28T18:13:25+00:00"
+        },
+        {
+            "name": "nette/neon",
+            "version": "v3.0.0",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/nette/neon.git",
+                "reference": "cbff32059cbdd8720deccf9e9eace6ee516f02eb"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/nette/neon/zipball/cbff32059cbdd8720deccf9e9eace6ee516f02eb",
+                "reference": "cbff32059cbdd8720deccf9e9eace6ee516f02eb",
+                "shasum": ""
+            },
+            "require": {
+                "ext-iconv": "*",
+                "ext-json": "*",
+                "php": ">=7.0"
+            },
+            "require-dev": {
+                "nette/tester": "^2.0",
+                "tracy/tracy": "^2.3"
+            },
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "3.0-dev"
+                }
+            },
+            "autoload": {
+                "classmap": [
+                    "src/"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "BSD-3-Clause",
+                "GPL-2.0",
+                "GPL-3.0"
+            ],
+            "authors": [
+                {
+                    "name": "David Grudl",
+                    "homepage": "https://davidgrudl.com"
+                },
+                {
+                    "name": "Nette Community",
+                    "homepage": "https://nette.org/contributors"
+                }
+            ],
+            "description": "? Nette NEON: encodes and decodes NEON file format.",
+            "homepage": "http://ne-on.org",
+            "keywords": [
+                "export",
+                "import",
+                "neon",
+                "nette",
+                "yaml"
+            ],
+            "time": "2019-02-05T21:30:40+00:00"
+        },
+        {
+            "name": "nette/php-generator",
+            "version": "v3.2.2",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/nette/php-generator.git",
+                "reference": "acff8b136fad84b860a626d133e791f95781f9f5"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/nette/php-generator/zipball/acff8b136fad84b860a626d133e791f95781f9f5",
+                "reference": "acff8b136fad84b860a626d133e791f95781f9f5",
+                "shasum": ""
+            },
+            "require": {
+                "nette/utils": "^2.4.2 || ~3.0.0",
+                "php": ">=7.1"
+            },
+            "require-dev": {
+                "nette/tester": "^2.0",
+                "tracy/tracy": "^2.3"
+            },
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "3.2-dev"
+                }
+            },
+            "autoload": {
+                "classmap": [
+                    "src/"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "BSD-3-Clause",
+                "GPL-2.0",
+                "GPL-3.0"
+            ],
+            "authors": [
+                {
+                    "name": "David Grudl",
+                    "homepage": "https://davidgrudl.com"
+                },
+                {
+                    "name": "Nette Community",
+                    "homepage": "https://nette.org/contributors"
+                }
+            ],
+            "description": "🐘 Nette PHP Generator: generates neat PHP code for you. Supports new PHP 7.3 features.",
+            "homepage": "https://nette.org",
+            "keywords": [
+                "code",
+                "nette",
+                "php",
+                "scaffolding"
+            ],
+            "time": "2019-03-15T03:41:13+00:00"
+        },
+        {
+            "name": "nette/robot-loader",
+            "version": "v3.2.0",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/nette/robot-loader.git",
+                "reference": "0712a0e39ae7956d6a94c0ab6ad41aa842544b5c"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/nette/robot-loader/zipball/0712a0e39ae7956d6a94c0ab6ad41aa842544b5c",
+                "reference": "0712a0e39ae7956d6a94c0ab6ad41aa842544b5c",
+                "shasum": ""
+            },
+            "require": {
+                "ext-tokenizer": "*",
+                "nette/finder": "^2.5",
+                "nette/utils": "^3.0",
+                "php": ">=7.1"
+            },
+            "require-dev": {
+                "nette/tester": "^2.0",
+                "tracy/tracy": "^2.3"
+            },
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "3.2-dev"
+                }
+            },
+            "autoload": {
+                "classmap": [
+                    "src/"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "BSD-3-Clause",
+                "GPL-2.0",
+                "GPL-3.0"
+            ],
+            "authors": [
+                {
+                    "name": "David Grudl",
+                    "homepage": "https://davidgrudl.com"
+                },
+                {
+                    "name": "Nette Community",
+                    "homepage": "https://nette.org/contributors"
+                }
+            ],
+            "description": "? Nette RobotLoader: high performance and comfortable autoloader that will search and autoload classes within your application.",
+            "homepage": "https://nette.org",
+            "keywords": [
+                "autoload",
+                "class",
+                "interface",
+                "nette",
+                "trait"
+            ],
+            "time": "2019-03-08T21:57:24+00:00"
+        },
+        {
+            "name": "nette/schema",
+            "version": "v1.0.0",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/nette/schema.git",
+                "reference": "6241d8d4da39e825dd6cb5bfbe4242912f4d7e4d"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/nette/schema/zipball/6241d8d4da39e825dd6cb5bfbe4242912f4d7e4d",
+                "reference": "6241d8d4da39e825dd6cb5bfbe4242912f4d7e4d",
+                "shasum": ""
+            },
+            "require": {
+                "nette/utils": "^3.0.1",
+                "php": ">=7.1"
+            },
+            "require-dev": {
+                "nette/tester": "^2.2",
+                "tracy/tracy": "^2.3"
+            },
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "1.0-dev"
+                }
+            },
+            "autoload": {
+                "classmap": [
+                    "src/"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "BSD-3-Clause",
+                "GPL-2.0",
+                "GPL-3.0"
+            ],
+            "authors": [
+                {
+                    "name": "David Grudl",
+                    "homepage": "https://davidgrudl.com"
+                },
+                {
+                    "name": "Nette Community",
+                    "homepage": "https://nette.org/contributors"
+                }
+            ],
+            "description": "📐 Nette Schema: validating data structures against a given Schema.",
+            "homepage": "https://nette.org",
+            "keywords": [
+                "config",
+                "nette"
+            ],
+            "time": "2019-04-03T15:53:25+00:00"
+        },
+        {
+            "name": "nette/utils",
+            "version": "v3.0.1",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/nette/utils.git",
+                "reference": "bd961f49b211997202bda1d0fbc410905be370d4"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/nette/utils/zipball/bd961f49b211997202bda1d0fbc410905be370d4",
+                "reference": "bd961f49b211997202bda1d0fbc410905be370d4",
+                "shasum": ""
+            },
+            "require": {
+                "php": ">=7.1"
+            },
+            "require-dev": {
+                "nette/tester": "~2.0",
+                "tracy/tracy": "^2.3"
+            },
+            "suggest": {
+                "ext-gd": "to use Image",
+                "ext-iconv": "to use Strings::webalize() and toAscii()",
+                "ext-intl": "to use Strings::webalize(), toAscii(), normalize() and compare()",
+                "ext-json": "to use Nette\\Utils\\Json",
+                "ext-mbstring": "to use Strings::lower() etc...",
+                "ext-xml": "to use Strings::length() etc. when mbstring is not available"
+            },
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "3.0-dev"
+                }
+            },
+            "autoload": {
+                "classmap": [
+                    "src/"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "BSD-3-Clause",
+                "GPL-2.0",
+                "GPL-3.0"
+            ],
+            "authors": [
+                {
+                    "name": "David Grudl",
+                    "homepage": "https://davidgrudl.com"
+                },
+                {
+                    "name": "Nette Community",
+                    "homepage": "https://nette.org/contributors"
+                }
+            ],
+            "description": "🛠 Nette Utils: lightweight utilities for string & array manipulation, image handling, safe JSON encoding/decoding, validation, slug or strong password generating etc.",
+            "homepage": "https://nette.org",
+            "keywords": [
+                "array",
+                "core",
+                "datetime",
+                "images",
+                "json",
+                "nette",
+                "paginator",
+                "password",
+                "slugify",
+                "string",
+                "unicode",
+                "utf-8",
+                "utility",
+                "validation"
+            ],
+            "time": "2019-03-22T01:00:30+00:00"
+        },
         {
             "name": "nikic/php-parser",
             "version": "v4.2.1",
@@ -916,6 +1534,56 @@
             ],
             "time": "2019-02-16T20:54:15+00:00"
         },
+        {
+            "name": "ocramius/package-versions",
+            "version": "1.4.0",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/Ocramius/PackageVersions.git",
+                "reference": "a4d4b60d0e60da2487bd21a2c6ac089f85570dbb"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/Ocramius/PackageVersions/zipball/a4d4b60d0e60da2487bd21a2c6ac089f85570dbb",
+                "reference": "a4d4b60d0e60da2487bd21a2c6ac089f85570dbb",
+                "shasum": ""
+            },
+            "require": {
+                "composer-plugin-api": "^1.0.0",
+                "php": "^7.1.0"
+            },
+            "require-dev": {
+                "composer/composer": "^1.6.3",
+                "doctrine/coding-standard": "^5.0.1",
+                "ext-zip": "*",
+                "infection/infection": "^0.7.1",
+                "phpunit/phpunit": "^7.0.0"
+            },
+            "type": "composer-plugin",
+            "extra": {
+                "class": "PackageVersions\\Installer",
+                "branch-alias": {
+                    "dev-master": "2.0.x-dev"
+                }
+            },
+            "autoload": {
+                "psr-4": {
+                    "PackageVersions\\": "src/PackageVersions"
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Marco Pivetta",
+                    "email": "ocramius@gmail.com"
+                }
+            ],
+            "description": "Composer plugin that provides efficient querying for installed package versions (no runtime IO)",
+            "time": "2019-02-21T12:16:21+00:00"
+        },
         {
             "name": "phar-io/manifest",
             "version": "1.0.3",
@@ -1074,16 +1742,16 @@
         },
         {
             "name": "phpdocumentor/reflection-docblock",
-            "version": "4.3.0",
+            "version": "4.3.1",
             "source": {
                 "type": "git",
                 "url": "https://github.com/phpDocumentor/ReflectionDocBlock.git",
-                "reference": "94fd0001232e47129dd3504189fa1c7225010d08"
+                "reference": "bdd9f737ebc2a01c06ea7ff4308ec6697db9b53c"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/phpDocumentor/ReflectionDocBlock/zipball/94fd0001232e47129dd3504189fa1c7225010d08",
-                "reference": "94fd0001232e47129dd3504189fa1c7225010d08",
+                "url": "https://api.github.com/repos/phpDocumentor/ReflectionDocBlock/zipball/bdd9f737ebc2a01c06ea7ff4308ec6697db9b53c",
+                "reference": "bdd9f737ebc2a01c06ea7ff4308ec6697db9b53c",
                 "shasum": ""
             },
             "require": {
@@ -1121,7 +1789,7 @@
                 }
             ],
             "description": "With this component, a library can provide support for annotations via DocBlocks or otherwise retrieve information that is embedded in a DocBlock.",
-            "time": "2017-11-30T07:14:17+00:00"
+            "time": "2019-04-30T17:48:53+00:00"
         },
         {
             "name": "phpdocumentor/type-resolver",
@@ -1280,6 +1948,79 @@
             "description": "PHPDoc parser with support for nullable, intersection and generic types",
             "time": "2019-04-23T20:26:19+00:00"
         },
+        {
+            "name": "phpstan/phpstan",
+            "version": "0.11.6",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/phpstan/phpstan.git",
+                "reference": "7af8b9d02b3ab36444dbf4e1b9ca1c1bd5044d81"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/phpstan/phpstan/zipball/7af8b9d02b3ab36444dbf4e1b9ca1c1bd5044d81",
+                "reference": "7af8b9d02b3ab36444dbf4e1b9ca1c1bd5044d81",
+                "shasum": ""
+            },
+            "require": {
+                "composer/xdebug-handler": "^1.3.0",
+                "jean85/pretty-package-versions": "^1.0.3",
+                "nette/bootstrap": "^2.4 || ^3.0",
+                "nette/di": "^2.4.7 || ^3.0",
+                "nette/robot-loader": "^3.0.1",
+                "nette/utils": "^2.4.5 || ^3.0",
+                "nikic/php-parser": "^4.0.2",
+                "php": "~7.1",
+                "phpstan/phpdoc-parser": "^0.3",
+                "symfony/console": "~3.2 || ~4.0",
+                "symfony/finder": "~3.2 || ~4.0"
+            },
+            "conflict": {
+                "symfony/console": "3.4.16 || 4.1.5"
+            },
+            "require-dev": {
+                "brianium/paratest": "^2.0",
+                "consistence/coding-standard": "^3.5",
+                "dealerdirect/phpcodesniffer-composer-installer": "^0.4.4",
+                "ext-intl": "*",
+                "ext-mysqli": "*",
+                "ext-soap": "*",
+                "ext-zip": "*",
+                "jakub-onderka/php-parallel-lint": "^1.0",
+                "localheinz/composer-normalize": "^1.1.0",
+                "phing/phing": "^2.16.0",
+                "phpstan/phpstan-deprecation-rules": "^0.11",
+                "phpstan/phpstan-php-parser": "^0.11",
+                "phpstan/phpstan-phpunit": "^0.11",
+                "phpstan/phpstan-strict-rules": "^0.11",
+                "phpunit/phpunit": "^7.0",
+                "slevomat/coding-standard": "^4.7.2",
+                "squizlabs/php_codesniffer": "^3.3.2"
+            },
+            "bin": [
+                "bin/phpstan"
+            ],
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "0.11-dev"
+                }
+            },
+            "autoload": {
+                "psr-4": {
+                    "PHPStan\\": [
+                        "src/",
+                        "build/PHPStan"
+                    ]
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "description": "PHPStan - PHP Static Analysis Tool",
+            "time": "2019-05-08T16:33:56+00:00"
+        },
         {
             "name": "phpunit/php-code-coverage",
             "version": "7.0.3",
@@ -1534,16 +2275,16 @@
         },
         {
             "name": "phpunit/phpunit",
-            "version": "8.1.3",
+            "version": "8.1.5",
             "source": {
                 "type": "git",
                 "url": "https://github.com/sebastianbergmann/phpunit.git",
-                "reference": "2a676677982b484ee36b54961f570c02eabbe7e1"
+                "reference": "01392d4b5878aa617e8d9bc7a529e5febc8fe956"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/sebastianbergmann/phpunit/zipball/2a676677982b484ee36b54961f570c02eabbe7e1",
-                "reference": "2a676677982b484ee36b54961f570c02eabbe7e1",
+                "url": "https://api.github.com/repos/sebastianbergmann/phpunit/zipball/01392d4b5878aa617e8d9bc7a529e5febc8fe956",
+                "reference": "01392d4b5878aa617e8d9bc7a529e5febc8fe956",
                 "shasum": ""
             },
             "require": {
@@ -1612,7 +2353,54 @@
                 "testing",
                 "xunit"
             ],
-            "time": "2019-04-19T15:52:00+00:00"
+            "time": "2019-05-14T04:57:31+00:00"
+        },
+        {
+            "name": "psr/log",
+            "version": "1.1.0",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/php-fig/log.git",
+                "reference": "6c001f1daafa3a3ac1d8ff69ee4db8e799a654dd"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/php-fig/log/zipball/6c001f1daafa3a3ac1d8ff69ee4db8e799a654dd",
+                "reference": "6c001f1daafa3a3ac1d8ff69ee4db8e799a654dd",
+                "shasum": ""
+            },
+            "require": {
+                "php": ">=5.3.0"
+            },
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "1.0.x-dev"
+                }
+            },
+            "autoload": {
+                "psr-4": {
+                    "Psr\\Log\\": "Psr/Log/"
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "PHP-FIG",
+                    "homepage": "http://www.php-fig.org/"
+                }
+            ],
+            "description": "Common interface for logging libraries",
+            "homepage": "https://github.com/php-fig/log",
+            "keywords": [
+                "log",
+                "psr",
+                "psr-3"
+            ],
+            "time": "2018-11-20T15:27:04+00:00"
         },
         {
             "name": "sebastian/code-unit-reverse-lookup",
@@ -1781,16 +2569,16 @@
         },
         {
             "name": "sebastian/environment",
-            "version": "4.2.1",
+            "version": "4.2.2",
             "source": {
                 "type": "git",
                 "url": "https://github.com/sebastianbergmann/environment.git",
-                "reference": "3095910f0f0fb155ac4021fc51a4a7a39ac04e8a"
+                "reference": "f2a2c8e1c97c11ace607a7a667d73d47c19fe404"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/sebastianbergmann/environment/zipball/3095910f0f0fb155ac4021fc51a4a7a39ac04e8a",
-                "reference": "3095910f0f0fb155ac4021fc51a4a7a39ac04e8a",
+                "url": "https://api.github.com/repos/sebastianbergmann/environment/zipball/f2a2c8e1c97c11ace607a7a667d73d47c19fe404",
+                "reference": "f2a2c8e1c97c11ace607a7a667d73d47c19fe404",
                 "shasum": ""
             },
             "require": {
@@ -1830,7 +2618,7 @@
                 "environment",
                 "hhvm"
             ],
-            "time": "2019-04-25T07:55:20+00:00"
+            "time": "2019-05-05T09:05:15+00:00"
         },
         {
             "name": "sebastian/exporter",
@@ -2276,7 +3064,7 @@
         },
         {
             "name": "symfony/console",
-            "version": "v4.2.7",
+            "version": "v4.2.8",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/console.git",
@@ -2348,16 +3136,16 @@
         },
         {
             "name": "symfony/contracts",
-            "version": "v1.0.2",
+            "version": "v1.1.0",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/contracts.git",
-                "reference": "1aa7ab2429c3d594dd70689604b5cf7421254cdf"
+                "reference": "d3636025e8253c6144358ec0a62773cae588395b"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/contracts/zipball/1aa7ab2429c3d594dd70689604b5cf7421254cdf",
-                "reference": "1aa7ab2429c3d594dd70689604b5cf7421254cdf",
+                "url": "https://api.github.com/repos/symfony/contracts/zipball/d3636025e8253c6144358ec0a62773cae588395b",
+                "reference": "d3636025e8253c6144358ec0a62773cae588395b",
                 "shasum": ""
             },
             "require": {
@@ -2365,19 +3153,22 @@
             },
             "require-dev": {
                 "psr/cache": "^1.0",
-                "psr/container": "^1.0"
+                "psr/container": "^1.0",
+                "symfony/polyfill-intl-idn": "^1.10"
             },
             "suggest": {
                 "psr/cache": "When using the Cache contracts",
                 "psr/container": "When using the Service contracts",
                 "symfony/cache-contracts-implementation": "",
+                "symfony/event-dispatcher-implementation": "",
+                "symfony/http-client-contracts-implementation": "",
                 "symfony/service-contracts-implementation": "",
                 "symfony/translation-contracts-implementation": ""
             },
             "type": "library",
             "extra": {
                 "branch-alias": {
-                    "dev-master": "1.0-dev"
+                    "dev-master": "1.1-dev"
                 }
             },
             "autoload": {
@@ -2412,7 +3203,56 @@
                 "interoperability",
                 "standards"
             ],
-            "time": "2018-12-05T08:06:11+00:00"
+            "time": "2019-04-27T14:29:50+00:00"
+        },
+        {
+            "name": "symfony/finder",
+            "version": "v4.2.8",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/symfony/finder.git",
+                "reference": "e45135658bd6c14b61850bf131c4f09a55133f69"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/symfony/finder/zipball/e45135658bd6c14b61850bf131c4f09a55133f69",
+                "reference": "e45135658bd6c14b61850bf131c4f09a55133f69",
+                "shasum": ""
+            },
+            "require": {
+                "php": "^7.1.3"
+            },
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "4.2-dev"
+                }
+            },
+            "autoload": {
+                "psr-4": {
+                    "Symfony\\Component\\Finder\\": ""
+                },
+                "exclude-from-classmap": [
+                    "/Tests/"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Fabien Potencier",
+                    "email": "fabien@symfony.com"
+                },
+                {
+                    "name": "Symfony Community",
+                    "homepage": "https://symfony.com/contributors"
+                }
+            ],
+            "description": "Symfony Finder Component",
+            "homepage": "https://symfony.com",
+            "time": "2019-04-06T13:51:08+00:00"
         },
         {
             "name": "symfony/polyfill-ctype",
diff --git a/tests/Unit/TtlTest.php b/tests/Unit/TtlTest.php
index 10ce703..cf633c1 100644
--- a/tests/Unit/TtlTest.php
+++ b/tests/Unit/TtlTest.php
@@ -13,6 +13,14 @@ public function testConstructorThrowsWhenTtlIsNegative(): void
         $this->expectException(InvalidTtl::class);
         $this->expectExceptionMessage('TTL can not be in the past.');
 
+        new Ttl(-1);
+    }
+
+    public function testConstructorThrowsWhenTtlIsMoreNegative(): void
+    {
+        $this->expectException(InvalidTtl::class);
+        $this->expectExceptionMessage('TTL can not be in the past.');
+
         new Ttl(-3);
     }