log

type Logger interface {
	// New returns a new Logger that has this logger's context plus the given context
	New(key string, value interface{}) Logger
	AddField(key string, value interface{})
	Debug(msg string)
	Info(msg string)
	Warn(msg string)
	Error(err error)
	Fatal(err error)
	TimeTrack(time.Time, string, map[string]interface{})
	Event(e string, f map[string]interface{})
}