public static function getMessage($field, $rule) {

		if(false === is_string($field)) {
			return trigger_error(sprintf('Argument 1 passed to %s() must be of the type string, "%s" given', __METHOD__, gettype($field)), E_USER_ERROR);
		}

		if(false === is_string($rule)) {
			return trigger_error(sprintf('Argument 2 passed to %s() must be of the type string, "%s" given', __METHOD__, gettype($rule)), E_USER_ERROR);
		}

		if(true === isset(static :: $messages[$field][$rule])) {
			return static :: $messages[$field][$rule];
		}
	}