code: func (l *Logger) Error(format string, a ...interface{}) {
  	l.Log(LevelError, format, a...)
  }
docs: // Error logs a message indicating an error condition.
  // This method takes one or multiple parameters. If a single parameter
  // is provided, it will be treated as the log message. If multiple parameters
  // are provided, they will be passed to fmt.Sprintf() to generate the log message.