Remove PHP language features incompatible with 5.6

Author: JakeQZ

tests/Unit/CSSList/CSSListTest.php

@@ -15,8 +15,10 @@ final class CSSListTest extends TestCase
 {
     /**
      * @test
+     *
+     * @return void
      */
-    public function implementsCSSElement(): void
+    public function implementsCSSElement()
     {
         $subject = new ConcreteCSSList();
 

tests/Unit/CSSList/Fixtures/ConcreteCSSList.php

@@ -9,12 +9,20 @@
 
 final class ConcreteCSSList extends CSSList
 {
-    public function isRootList(): bool
+    /**
+     * @return never
+     */
+    public function isRootList()
     {
         throw new \BadMethodCallException('Not implemented', 1740395831);
     }
 
-    public function render(OutputFormat $outputFormat): string
+    /**
+     * @param OutputFormat|null $outputFormat
+     *
+     * @return never
+     */
+    public function render($outputFormat)
     {
         throw new \BadMethodCallException('Not implemented', 1740395836);
     }

tests/Unit/Rule/RuleTest.php

@@ -18,8 +18,10 @@ final class RuleTest extends TestCase
 {
     /**
      * @test
+     *
+     * @return void
      */
-    public function implementsCSSElement(): void
+    public function implementsCSSElement()
     {
         $subject = new Rule('beverage-container');
 

tests/Unit/RuleSet/Fixtures/ConcreteRuleSet.php

@@ -12,7 +12,7 @@ final class ConcreteRuleSet extends RuleSet
     /**
      * @return never
      */
-    public function render(OutputFormat $outputFormat): string
+    public function render(OutputFormat $outputFormat)
     {
         throw new \BadMethodCallException('Nothing to see here :/', 1744067015);
     }

tests/Unit/RuleSet/RuleSetTest.php

@@ -15,8 +15,10 @@ final class RuleSetTest extends TestCase
 {
     /**
      * @test
+     *
+     * @return void
      */
-    public function implementsCSSElement(): void
+    public function implementsCSSElement()
     {
         $subject = new ConcreteRuleSet();
 

tests/Unit/Value/Fixtures/ConcreteValue.php

@@ -12,7 +12,7 @@ final class ConcreteValue extends Value
     /**
      * @return never
      */
-    public function render(OutputFormat $outputFormat): string
+    public function render(OutputFormat $outputFormat)
     {
         throw new \BadMethodCallException('Nothing to see here :/', 1744067951);
     }

tests/Unit/Value/ValueTest.php

@@ -16,8 +16,10 @@ final class ValueTest extends TestCase
 {
     /**
      * @test
+     *
+     * @return void
      */
-    public function implementsCSSElement(): void
+    public function implementsCSSElement()
     {
         $subject = new ConcreteValue();