public async Task GetApiVersionsBadUrl()
        {
            AuthInfo    authInfo = forceClientFixture.AuthInfo;
            ForceClient client   = new ForceClient(authInfo);

            await Assert.ThrowsAsync <ForceApiException>(
                async() => await client.GetAvailableRestApiVersions("https://badurl")
                );
        }
        public async Task GetApiVersionsCustomUrl()
        {
            AuthInfo    authInfo = forceClientFixture.AuthInfo;
            ForceClient client   = new ForceClient(authInfo);

            List <SalesforceVersion> versions = await client.GetAvailableRestApiVersions(client.InstanceUrl);

            Assert.NotNull(versions);
            Assert.NotEmpty(versions);

            var sampleVersion = versions[0];

            Assert.True(!string.IsNullOrEmpty(sampleVersion.Label));
            Assert.True(!string.IsNullOrEmpty(sampleVersion.Url));
            Assert.True(!string.IsNullOrEmpty(sampleVersion.Version));
        }