public async Task GetUnassignedAsync()
{
// Arrange
var mockHttp = new MockHttpMessageHandler();
mockHttp.Expect(HttpMethod.Get, Utils.GetSendGridApiUri(ENDPOINT) + $"?exclude_whitelabels=false&limit=500&offset=0&sort_by_direction=asc").Respond("application/json", MULTIPLE_IPADDRESSES_JSON);
var client = Utils.GetFluentClient(mockHttp);
var ipAddresses = new IpAddresses(client);
// Act
var result = await ipAddresses.GetUnassignedAsync(CancellationToken.None).ConfigureAwait(false);
// Assert
mockHttp.VerifyNoOutstandingExpectation();
mockHttp.VerifyNoOutstandingRequest();
result.ShouldNotBeNull();
result.Length.ShouldBe(1);
}