log

type Logger interface {
	Infof(format string, v ...interface{})
	Warnf(format string, v ...interface{})
	Printf(format string, v ...interface{})
	Donef(format string, v ...interface{})
	Debugf(format string, v ...interface{})
	Errorf(format string, v ...interface{})
	TInfof(format string, v ...interface{})
	TWarnf(format string, v ...interface{})
	TPrintf(format string, v ...interface{})
	TDonef(format string, v ...interface{})
	TDebugf(format string, v ...interface{})
	TErrorf(format string, v ...interface{})
	Println()
	EnableDebugLog(enable bool)
}

type LoggerOptions func(*logger)

type Severity uint8