protected boolean isEmpty() {
        return invokerMap == null || invokerMap.isEmpty();
    }
Handle request from HTTP/2

@param streamId stream Id
@param request SofaRequest
@param ctx ChannelHandlerContext
@param encoder Http2ConnectionEncoder
remoting/remoting-http/src/main/java/com/alipay/sofa/rpc/server/http/HttpServerHandler.java