/// <summary>
 /// Create a StudentCohortAssociation object
 /// </summary>
 /// <param name="cs">the service to use for this action</param>
 /// <param name="associations">the StudentCohortAssociation to create</param>
 /// <returns>result of this action</returns>
 public static async Task<ActionResponseResult> CreateOneStudentCohortAssociation(CohortService cs, string cId, string sId)
 {
     var a = new StudentCohortAssociation { cohortId = cId, studentId = sId, beginDate = DateTime.Now };
     var result = await cs.CreateStudentCohortAssociation(a);
     var student = (StudentDisplayObject)HttpContext.Current.Cache[sId];
     return GlobalHelper.GetActionResponseResult(sId, student != null ? student.name : "", result, HttpStatusCode.Created);
 }
        public async Task<string> CreateOneAssociation(CohortService cs, string cId, Student s)
        {
            var a = new StudentCohortAssociation { cohortId = cId, studentId = s.id, beginDate = DateTime.Now };
            var result = await cs.CreateStudentCohortAssociation(a);

            return result.ToString();
        }