docs: @Override
    public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise)
            throws Exception {
      if (msg instanceof CreateStreamCommand) {
        createStream((CreateStreamCommand) msg, promise);
      } else if (msg instanceof SendGrpcFrameCommand) {
        sendGrpcFrame(ctx, (SendGrpcFrameCommand) msg, promise);
      } else if (msg instanceof CancelClientStreamCommand) {
        cancelStream(ctx, (CancelClientStreamCommand) msg, promise);
      } else if (msg instanceof SendPingCommand) {
        sendPingFrame(ctx, (SendPingCommand) msg, promise);
      } else if (msg instanceof GracefulCloseCommand) {
        gracefulClose(ctx, (GracefulCloseCommand) msg, promise);
      } else if (msg instanceof ForcefulCloseCommand) {
        forcefulClose(ctx, (ForcefulCloseCommand) msg, promise);
      } else if (msg == NOOP_MESSAGE) {
        ctx.write(Unpooled.EMPTY_BUFFER, promise);
      } else {
        throw new AssertionError("Write called for unexpected type: " + msg.getClass().getName());
      }
    }