writer.go
func (f *FileLogger) T(format string, v ...interface{}) {
	f.Trace(format, v...)
}
func (f *FileLogger) T(format string, v ...interface{}) {
	f.Trace(format, v...)
}
func ( f * FileLogger ) T ( format string , v ... interface { } ) { f . Trace ( format , v ... ) }
// same with Trace()
same with Trace ()