Method complete

valdi/test/utils/RequestManagerMock.cpp:21–34

        : _request(std::move(request)), _completion(std::move(completion)) {}

    void complete(const Result<snap::valdi_core::HTTPResponse>& result) {
        std::lock_guard<std::mutex> guard(_mutex);
        auto completion = std::move(_completion);
        if (completion == nullptr) {
            return;
        }
        _response = {result};

        if (result.success()) {
            completion->onComplete(result.value());
        } else {
            completion->onFail(result.error().toString());
        }
    }

    void cancel() override {
        std::lock_guard<std::mutex> guard(_mutex);