Function send_directory 

pub fn send_directory<S>(
    send: &mut S,
    root_path: &Path,
    files: &[FileSendRecvTree],
    write_callback: &mut impl FnMut(u64),
    should_continue: &mut impl FnMut() -> bool,
) -> Result<bool>
where
    S: AsyncWriteExt + Unpin + Send,

Returns

• Ok(true) if the transfer should continue
• Ok(false) if the transfer should stop