System.Net.WebSockets.ManagedWebSocket.SendAsync C# (CSharp) Method

        public override Task SendAsync(ArraySegment<byte> buffer, WebSocketMessageType messageType, bool endOfMessage, CancellationToken cancellationToken)
        {
            if (messageType != WebSocketMessageType.Text && messageType != WebSocketMessageType.Binary)
            {
                throw new ArgumentException(SR.Format(
                    SR.net_WebSockets_Argument_InvalidMessageType,
                    nameof(WebSocketMessageType.Close), nameof(SendAsync), nameof(WebSocketMessageType.Binary), nameof(WebSocketMessageType.Text), nameof(CloseOutputAsync)),
                    nameof(messageType));
            }
            WebSocketValidate.ValidateArraySegment(buffer, nameof(buffer));

            try
            {
                ClientWebSocket.ThrowIfInvalidState(_state, _disposed, s_validSendStates);
                ThrowIfOperationInProgress(_lastSendAsync);
            }
            catch (Exception exc)
            {
                return Task.FromException(exc);
            }

            MessageOpcode opcode =
                _lastSendWasFragment ? MessageOpcode.Continuation :
                messageType == WebSocketMessageType.Binary ? MessageOpcode.Binary :
                MessageOpcode.Text;

            Task t = SendFrameAsync(opcode, endOfMessage, buffer, cancellationToken);
            _lastSendWasFragment = !endOfMessage;
            _lastSendAsync = t;
            return t;
        }