original_string: private function walk(callable $cb)
      {
          foreach($this->values() as $key => $value) {
              $cb($key, $value);
          }
      }
code: private function walk(callable $cb)
      {
          foreach($this->values() as $key => $value) {
              $cb($key, $value);
          }
      }
code_tokens: private function walk ( callable $ cb ) { foreach ( $ this -> values ( ) as $ key => $ value ) { $ cb ( $ key , $ value ) ; } }
docstring: Apply a callback to each input value
docstring_tokens: Apply a callback to each input value