public async Task WhenFetchDataThenShouldGetAsync() { await _objectToTest.FetchData(_currencyPair, (sender, data) => { Assert.IsNotNull(data); }); _handlerMock.Protected().Verify( "SendAsync", Times.Once(), ItExpr.Is <HttpRequestMessage>(req => req.Method == HttpMethod.Get && req.RequestUri == new Uri(_httpClient.BaseAddress + _currencyPair) ), ItExpr.IsAny <CancellationToken>() ); }