public override async Task FlushAsync(CancellationToken cancellationToken)
{
await _webSocket.Connection.WriteInternalAsync(_webSocket.Connection.SendBuffer, _internalUsedBufferLength, false, _isHeaderSent, _messageType, ExtensionFlags, cancellationToken).ConfigureAwait(false);
_internalUsedBufferLength = 0;
_isHeaderSent = true;
}
public override void Close()