pub trait SealedSender {
// Required methods
fn poll_write(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &[u8],
) -> Poll<Result<usize, WsError>>;
fn poll_flush(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
) -> Poll<Result<(), WsError>>;
fn poll_close(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
msg: &mut Option<Message>,
) -> Poll<Result<(), WsError>>;
}