@Override
    protected RpcResponse doExecute(ClientRequestContext ctx, RpcRequest req) throws Exception {
        final CompletableFuture<RpcResponse> future = new CompletableFuture<>();
        final RpcResponse res = RpcResponse.from(future);
        doExecute0(ctx, req, res, future);
        return res;
    }
Creates a new instance that decorates the specified {@link RpcClient}.
core/src/main/java/com/linecorp/armeria/client/retry/RetryingRpcClient.java