private void handleWebSocketFrame(ChannelHandlerContext ctx, WebSocketFrame frame) {
        if (frame instanceof TextWebSocketFrame) {
            pojoEndpointServer.doOnMessage(ctx.channel(), frame);
            return;
        }
        if (frame instanceof PingWebSocketFrame) {
            ctx.writeAndFlush(new PongWebSocketFrame(frame.content().retain()));
            return;
        }
        if (frame instanceof CloseWebSocketFrame) {
            ctx.writeAndFlush(frame.retainedDuplicate()).addListener(ChannelFutureListener.CLOSE);
            return;
        }
        if (frame instanceof BinaryWebSocketFrame) {
            pojoEndpointServer.doOnBinary(ctx.channel(), frame);
            return;
        }
        if (frame instanceof PongWebSocketFrame) {
            return;
        }
    }