original_string: public function help($event_name, $callback)
      {
          if (!isset($this->event_helpers[$event_name]))
          {
              $this->event_helpers[$event_name] = $callback;
          }
      }
code: public function help($event_name, $callback)
      {
          if (!isset($this->event_helpers[$event_name]))
          {
              $this->event_helpers[$event_name] = $callback;
          }
      }
code_tokens: public function help ( $ event_name , $ callback ) { if ( ! isset ( $ this -> event_helpers [ $ event_name ] ) ) { $ this -> event_helpers [ $ event_name ] = $ callback ; } }
docstring: add a helper callback to an event
docstring_tokens: add a helper callback to an event