glg.go
func Get() *Glg {
	once.Do(func() {
		fastime.SetFormat(timeFormat)
		glg = New()
	})
	return glg
}
func Get() *Glg {
	once.Do(func() {
		fastime.SetFormat(timeFormat)
		glg = New()
	})
	return glg
}
// Get returns singleton glg instance