public static Function<? super RpcClient, RetryingRpcClient>
    newDecorator(RetryConfigMapping<RpcResponse> mapping) {
        return builder(mapping).newDecorator();
    }
Creates a new {@link RpcClient} decorator that handles failures of an invocation and retries
RPC requests.

@param mapping the mapping that returns a {@link RetryConfig} for a given {@link ClientRequestContext}
       and {@link Request}.
core/src/main/java/com/linecorp/armeria/client/retry/RetryingRpcClient.java