Rest API C#, RestSharp, and Newtonsoft Enrollments

Question

I am trying to use the API using C#, RestSharp, and Newtonsoft. I am trying to GET enrollments by Section Id. I have created classes to handle the JSON that is returned, but I am getting errors. The classes are listed below. [JsonObject]
public class Grades
{
public string html_url { get; set; }
public object current_grade { get; set; }
public object current_score { get; set; }
public object final_grade { get; set; }
public double final_score { get; set; }
public object unposted_current_score { get; set; }
public object unposted_current_grade { get; set; }
public double unposted_final_score { get; set; }
public object unposted_final_grade { get; set; }
}
[JsonObject]
public class User
{
public int id { get; set; }
public string name { get; set; }
public DateTime created_at { get; set; }
public string sortable_name { get; set; }
public string short_name { get; set; }
public object sis_user_id { get; set; }
public object integration_id { get; set; }
public object sis_import_id { get; set; }
public string login_id { get; set; }
}
[JsonObject]
public class Enrollment
{
public int id { get; set; }
public int user_id { get; set; }
public int course_id { get; set; }
public string type { get; set; }
public DateTime created_at { get; set; }
public DateTime updated_at { get; set; }
public object associated_user_id { get; set; }
public object start_at { get; set; }
public object end_at { get; set; }
public int course_section_id { get; set; }
public int root_account_id { get; set; }
public bool limit_privileges_to_course_section { get; set; }
public string enrollment_state { get; set; }
public string role { get; set; }
public int role_id { get; set; }
public object last_activity_at { get; set; }
public object last_attended_at { get; set; }
public int total_activity_time { get; set; }
public object sis_import_id { get; set; }
public Grades grades { get; set; }
public string sis_account_id { get; set; }
public string sis_course_id { get; set; }
public object course_integration_id { get; set; }
public string sis_section_id { get; set; }
public object section_integration_id { get; set; }
public object sis_user_id { get; set; }
public string html_url { get; set; }
public User user { get; set; }
}

public class RootObject
{
public List<Enrollment> enrollList { get; set; }
}‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ Below is the the function that is called to get the list of enrollments. public RootObject getListSectionEnrollments(string baseUrl, string section_id, string authToken, string[] type = null, string[] role = null, string[] state = null )
{
type = type ?? new string[] { "StudentEnrollment", "TeacherEnrollment", "TaEnrollment", "DesignerEnrollment", "ObserverEnrollment" };
role = role ?? new string[] { "StudentEnrollment", "TeacherEnrollment", "TaEnrollment", "DesignerEnrollment", "ObserverEnrollment" };
state = state ?? new string[] { "active", "invited" };

string apiCall = "/api/v1/sections/:section_id/enrollments".Replace(":section_id", section_id);
string url = baseUrl + apiCall;
var client = new RestClient(url);

var request = new RestRequest(Method.GET);

request.AddHeader("Authorization", "Bearer " + authToken);
request.AddParameter("type[]", type);
request.AddParameter("role[]", role);
request.AddParameter("state[]", state);

request.RequestFormat = DataFormat.Json;
var response = client.Execute(request);

RootObject myObject = JsonConvert.DeserializeObject<RootObject>(response.Content);
return myObject;
}‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ All the above code is in a public class called Enrollments. Which is then built into a dll that I use in my C# programs. The program calls the function like this. The second line is meant as a test to ensure that there is something in the enrollments object. Enrollments.RootObject enrollments = en.getListSectionEnrollments(ConStrings.canvasLiveBaseUrl, canvas_id, ConStrings.canvasProdToken, new string[] { "StudentEnrollment"});
MessageBox.Show(enrollments.enrollList.Count.ToString()); ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ The second line above causes the below error. Object reference not set to an instance of an object.System.NullReferenceException: Object reference not set to an instance of an object.‍