public TaxiViewModel()
{
Title = "Такси";
// todo: move taxis list to the server
Taxis = new ObservableCollection <Taxi>(Taxi.GetFakeTaxiList());
// todo: make a call directly
// http://www.c-sharpcorner.com/UploadFile/e4bad6/code-to-start-call-in-xamarin-forms/
// https://blog.falafel.com/dialing-a-number-in-xamarin-forms-using-dependencyservice/
// https://stackoverflow.com/questions/37551576/how-to-make-a-phone-call-in-xamarin-forms-by-clicking-on-a-label
// https://stackoverflow.com/questions/33880505/make-phone-call-directly-xamarin-forms
// https://www.youtube.com/watch?v=szYSHnvnTrk
// http://nugetmusthaves.com/Package/PhoneCall.Forms.Plugin
MakeACallCommand = new Command((tel) => Device.OpenUri(new Uri("tel:" + tel.ToString())));
}