@Deprecated
    @Override
    public GrpcClientBuilder rpcDecorator(DecoratingRpcClientFunction decorator) {
        throw new UnsupportedOperationException("rpcDecorator() does not support gRPC. " +
                                                "Use either decorator() or intercept()");
    }
Unsupported operation. {@code rpcDecorator} only supports Thrift.
@deprecated Use either {@link #decorator(DecoratingHttpClientFunction)} or
            {@link #intercept(ClientInterceptor...)} instead.
grpc/src/main/java/com/linecorp/armeria/client/grpc/GrpcClientBuilder.java