private async Task <List <ContactCandidate> > GetGraphContactsAsync()
        {
            var optionList = new List <QueryOption>();
            var columns    = "id,displayName,homePhones,mobilePhone,businessPhones";

            optionList.Add(new QueryOption("$select", columns));

            IUserContactsCollectionPage contacts;

            try
            {
                contacts = await this._graphClient.Me.Contacts.Request(optionList).GetAsync();
            }
            catch (ServiceException ex)
            {
                throw GraphClient.HandleGraphAPIException(ex);
            }

            return(ToContactCandidates(contacts));
        }
        private async Task <List <ContactCandidate> > GetPeopleAsync()
        {
            var optionList = new List <QueryOption>();
            var columns    = "id,displayName,phones";

            optionList.Add(new QueryOption("$select", columns));

            IUserPeopleCollectionPage people;

            try
            {
                people = await this._graphClient.Me.People.Request(optionList).GetAsync();
            }
            catch (ServiceException ex)
            {
                throw GraphClient.HandleGraphAPIException(ex);
            }

            return(ToContactCandidates(people));
        }