internal/bufio/bufio.go
func (w *Writer) WriteInt64(i int64) {
	if w.err != nil {
		return
	}
	binary.LittleEndian.PutUint64(w.b[:8], uint64(i))
	w.wr.Write(w.b[:8])
}
func (w *Writer) WriteInt64(i int64) {
	if w.err != nil {
		return
	}
	binary.LittleEndian.PutUint64(w.b[:8], uint64(i))
	w.wr.Write(w.b[:8])
}
// WriteInt64 writes an int64.