protected function _getOutputPlain($data) {
		// create output string
		$output = 'date: '.$data['formated_time'].' .'.$data['formated_microtime']."\n";
		$output .= 'call: '.$data['caller']['file'].' (line '.$data['caller']['line'].')'."\n";

		foreach ($data['args'] as $arg) {
			$output .= '---'."\n";

			// get dump
			ob_start();
			var_dump($arg);
			$dump = ob_get_clean();
			
			$output .= $dump;
		}

		$output .= '=============================='."\n";

		$result =  file_put_contents($this->_logfile, $output, FILE_APPEND);
		if (is_integer($result)) return true;
		else return false;
	}