log.go
func (l *slog) Debug(args ...interface{}) {
	lvl := l.Level()
	if lvl <= LevelDebug {
		l.b.print("DBG", l.tag, args...)
	}
}
func (l *slog) Debug(args ...interface{}) {
	lvl := l.Level()
	if lvl <= LevelDebug {
		l.b.print("DBG", l.tag, args...)
	}
}
// Debug formats message using the default formats for its operands, prepends
// the prefix as necessary, and writes to log with LevelDebug.
//
// This is part of the Logger interface implementation.