original_string: public function add($name, $callback, $error_message) {
  		$this->_callbacks[$name] = $callback;
  		$this->_messages[$name] = $error_message;
  	}
code: public function add($name, $callback, $error_message) {
  		$this->_callbacks[$name] = $callback;
  		$this->_messages[$name] = $error_message;
  	}
code_tokens: public function add ( $ name , $ callback , $ error_message ) { $ this -> _callbacks [ $ name ] = $ callback ; $ this -> _messages [ $ name ] = $ error_message ; }
docstring: Adds a user defined validator.
  @param	string	$name	The name of the validator.
  @param	callable	$callback	A valid PHP callback like `['OBJECT', 'METHOD']`, `[$obj, 'METHOD']` or a n anonymous function like `function($input, $value){}`. The method gets at least two parameters passed. An array of all `$input` parameters and the `$value` to validate. Other parameters are the passed parameters.
  @param	string	$error_message	The error message that get all parameters passed via `sprintf`, so you can use `%s` and other `sprintf` replacements.
docstring_tokens: Adds a user defined validator .