[CLEANUP] Rector: Add missing return type declaration based on parent class method (#606)

This applies the rule AddReturnTypeDeclarationBasedOnParentClassMethodRector. For
Details see:
https://github.com/rectorphp/rector/blob/main/docs/rector_rules_overview.md#addreturntypedeclarationbasedonparentclassmethodrector

Signed-off-by: Daniel Ziegenberg <daniel@ziegenberg.at>

Author: ziegenberg

src/CSSList/AtRuleBlockList.php

@@ -48,10 +48,7 @@ public function atRuleArgs()
         return $this->sArgs;
     }
 
-    /**
-     * @return string
-     */
-    public function __toString()
+    public function __toString(): string
     {
         return $this->render(new OutputFormat());
     }

src/CSSList/CSSList.php

@@ -394,10 +394,7 @@ public function removeDeclarationBlockBySelector($mSelector, $bRemoveAll = false
         }
     }
 
-    /**
-     * @return string
-     */
-    public function __toString()
+    public function __toString(): string
     {
         return $this->render(new OutputFormat());
     }

src/CSSList/KeyFrame.php

@@ -59,10 +59,7 @@ public function getAnimationName()
         return $this->animationName;
     }
 
-    /**
-     * @return string
-     */
-    public function __toString()
+    public function __toString(): string
     {
         return $this->render(new OutputFormat());
     }

src/Comment/Comment.php

@@ -51,10 +51,7 @@ public function setComment($sComment): void
         $this->sComment = $sComment;
     }
 
-    /**
-     * @return string
-     */
-    public function __toString()
+    public function __toString(): string
     {
         return $this->render(new OutputFormat());
     }

src/Property/CSSNamespace.php

@@ -51,10 +51,7 @@ public function getLineNo()
         return $this->iLineNo;
     }
 
-    /**
-     * @return string
-     */
-    public function __toString()
+    public function __toString(): string
     {
         return $this->render(new OutputFormat());
     }

src/Property/Charset.php

@@ -69,10 +69,7 @@ public function getCharset()
         return $this->oCharset->getString();
     }
 
-    /**
-     * @return string
-     */
-    public function __toString()
+    public function __toString(): string
     {
         return $this->render(new OutputFormat());
     }

src/Property/Import.php

@@ -68,10 +68,7 @@ public function getLocation()
         return $this->oLocation;
     }
 
-    /**
-     * @return string
-     */
-    public function __toString()
+    public function __toString(): string
     {
         return $this->render(new OutputFormat());
     }

src/Property/Selector.php

@@ -113,10 +113,7 @@ public function setSelector($sSelector): void
         $this->iSpecificity = null;
     }
 
-    /**
-     * @return string
-     */
-    public function __toString()
+    public function __toString(): string
     {
         return $this->getSelector();
     }

src/Rule/Rule.php

@@ -247,10 +247,7 @@ public function getIsImportant()
         return $this->bIsImportant;
     }
 
-    /**
-     * @return string
-     */
-    public function __toString()
+    public function __toString(): string
     {
         return $this->render(new OutputFormat());
     }

src/RuleSet/AtRuleSet.php

@@ -51,10 +51,7 @@ public function atRuleArgs()
         return $this->sArgs;
     }
 
-    /**
-     * @return string
-     */
-    public function __toString()
+    public function __toString(): string
     {
         return $this->render(new OutputFormat());
     }