log_adapter.go
func (la *LogAdapter) Warning(msg string) error {
	return la.Log(LevelWarning, nil, msg)
}
func (la *LogAdapter) Warning(msg string) error {
	return la.Log(LevelWarning, nil, msg)
}
/*
Warning uses msg as a format string with subsequent parameters as values and logs
the resulting message to all added loggers at LogLevel.LevelWarning
*/