typed/buffer.go
func (w *WriteBuffer) FlushTo(iow io.Writer) (int, error) {
	dirty := w.buffer[0:w.BytesWritten()]
	return iow.Write(dirty)
}
func (w *WriteBuffer) FlushTo(iow io.Writer) (int, error) {
	dirty := w.buffer[0:w.BytesWritten()]
	return iow.Write(dirty)
}
// FlushTo flushes the written buffer to the given writer