@SuppressWarnings("rawtypes")
            @Override
            public ServerCall.Listener<W> startCall(final ServerCall<W, M> call, final Metadata headers) {
                final ServerCall<R, P> unwrappedCall = new JsonForwardingServerCall<>((ServerCall<P, P>) call);
                final ServerCall.Listener<R> originalListener = originalHandler.startCall(unwrappedCall, headers);
                return new JsonServerCallListener(originalListener, unwrappedCall);
            }
wrap handler.
@param originalHandler original handler
@param <R> origin request message
@param <P> origin response message
@param <W> wrap request message
@param <M> wrap response message
@return wrap handler
shenyu-client/shenyu-client-grpc/src/main/java/org/apache/shenyu/client/grpc/json/JsonServerServiceInterceptor.java