/// <summary>
        /// Performs query operation for available <see cref="Interviewer"/>s asynchronously.
        /// Note that this sample does not return the result, although your real class will do so.
        /// </summary>
        public void QueryForInterviewersAsync()
        {
            // execute async call
            Task <IQueryable <Interviewer> > task = _interviewersService.QueryAsync();

            // do some work here
            // ...

            // get async call result
            IEnumerable <Interviewer> allInterviewers = task.Result.ToList();

            IEnumerable <Interviewer> interviewersWithValidTelephone =
                allInterviewers.Where(interviewer => !string.IsNullOrEmpty(interviewer.TelephoneNumber)).ToList();
        }
 /// <summary>
 /// A synchronous version of <see cref="INfieldInterviewersService.QueryAsync"/>
 /// </summary>
 public static IQueryable <Interviewer> Query(this INfieldInterviewersService interviewersService)
 {
     return(interviewersService.QueryAsync().Result);
 }