Added CLOSURE_RETURN_TYPE_ERROR to Exception

lib/Exception.php

@@ -18,6 +18,7 @@ class Exception extends \Exception {
     const READONLY_PROPERTY = 202;
     const ARGUMENT_TYPE_ERROR = 203;
     const UNDEFINED_METHOD = 204;
+    const CLOSURE_RETURN_TYPE_ERROR = 205;
 
 
     protected static $messages = [
@@ -29,7 +30,8 @@ class Exception extends \Exception {
         201 => 'Property %s does not exist',
         202 => 'Cannot write readonly property %s',
         203 => 'Argument #%s ($%s) must be of type %s, %s given',
-        204 => 'Call to undefined method %s::%s()'
+        204 => 'Call to undefined method %s::%s()',
+        205 => 'Closure must return type %s, %s given'
     ];
 
     public function __construct(int $code, ...$args) {