logger

type Logger interface {
	Trace(msg string, fields sdk.Fields)
	Debug(msg string, fields sdk.Fields)
	Info(msg string, fields sdk.Fields)
	Notice(msg string, fields sdk.Fields)
	Warning(msg string, fields sdk.Fields)
	Error(msg string, fields sdk.Fields)
	Fatal(msg string, fields sdk.Fields)
	SetLevel(level string)
	NewLogger(id, name string, add bool) Logger
	Remove()
	NewStdLogger(prefix string, flag int, level string) *log.Logger
}