code: func (c *Device) OpenWrite(path string, perms os.FileMode, mtime time.Time) (io.WriteCloser, error) {
  	conn, err := c.getSyncConn()
  	if err != nil {
  		return nil, wrapClientError(err, c, "OpenWrite(%s)", path)
  	}
  
  	writer, err := sendFile(conn, path, perms, mtime)
  	return writer, wrapClientError(err, c, "OpenWrite(%s)", path)
  }
docs: // OpenWrite opens the file at path on the device, creating it with the permissions specified
  // by perms if necessary, and returns a writer that writes to the file.
  // The files modification time will be set to mtime when the WriterCloser is closed. The zero value
  // is TimeOfClose, which will use the time the Close method is called as the modification time.