Consistent type-hints for static returns.

src/Whoops/Handler/JsonResponseHandler.php

@@ -28,7 +28,7 @@ class JsonResponseHandler extends Handler
     /**
      * Returns errors[[]] instead of error[] to be in compliance with the json:api spec
      * @param bool $jsonApi Default is false
-     * @return $this
+     * @return static
      */
     public function setJsonApi($jsonApi = false)
     {
@@ -38,7 +38,7 @@ class JsonResponseHandler extends Handler
 
     /**
      * @param  bool|null  $returnFrames
-     * @return bool|$this
+     * @return bool|static
      */
     public function addTraceToOutput($returnFrames = null)
     {

src/Whoops/Handler/PlainTextHandler.php

@@ -108,7 +108,7 @@ class PlainTextHandler extends Handler
     /**
      * Add error trace to output.
      * @param  bool|null  $addTraceToOutput
-     * @return bool|$this
+     * @return bool|static
      */
     public function addTraceToOutput($addTraceToOutput = null)
     {
@@ -123,7 +123,7 @@ class PlainTextHandler extends Handler
     /**
      * Add previous exceptions to output.
      * @param  bool|null $addPreviousToOutput
-     * @return bool|$this
+     * @return bool|static
      */
     public function addPreviousToOutput($addPreviousToOutput = null)
     {

src/Whoops/Handler/XmlResponseHandler.php

@@ -23,7 +23,7 @@ class XmlResponseHandler extends Handler
 
     /**
      * @param  bool|null  $returnFrames
-     * @return bool|$this
+     * @return bool|static
      */
     public function addTraceToOutput($returnFrames = null)
     {