发出 Moq'ing HttpResponseMessage

Question

我有以下方法：public async Task<SecurityRoleDeleteResult> DeleteSecurityRoleByRoleId(int securityRoleId){    string url = $"{_housingDataSecurityConfiguration.HousingDataSecurityWebApiUrl}SecurityRoles/Delete";    HttpResponseMessage message = _apiClientService.Post(url, securityRoleId);    if (message.StatusCode == HttpStatusCode.InternalServerError)    {        return SecurityRoleDeleteResult.ErrorOccurred;    }    int intResult = 0;    var apiResult = await message.Content.ReadAsStringAsync();    if (int.TryParse(apiResult, out intResult))    {        return (SecurityRoleDeleteResult)intResult;    }    else    {        return SecurityRoleDeleteResult.ErrorOccurred;    }}我现在正在尝试为它编写一个单元测试，到目前为止：[Test]public async Task DeleteSecurityRoleByRoleId(){    _mockApiClientService.Setup(a => a.Post(It.IsAny<string>(), It.IsAny<int>()))        .Returns(new HttpResponseMessage {StatusCode = HttpStatusCode.OK});    SecurityRoleDeleteResult result = await _securityRoleService.DeleteSecurityRoleByRoleId(It.IsAny<int>());    Assert.AreEqual(SecurityRoleDeleteResult.Success, result);}这里的问题是，当_securityRoleService.DeleteSecurityRoleByRoleId我在方法中运行测试时，我尝试将var apiResultmessage.content设置为 null，因为在这种情况下，我只是在模拟崩溃。我怎样才能模拟这个以便我的测试能够工作？