/// <summary>
/// Update PatientLists when the Practitioner changes
/// </summary>
/// <param name="subject"></param>
/// <returns></returns>
public async Task UpdateAsync(IObservableSubject subject)
{
IsLoading = true;
if (_practitioner == null || (subject as Practitioner).Id != _practitioner.Id)
{
_practitioner = (Practitioner)subject;
_patients = await FhirService.GetPatientsOfPractitioner(_practitioner.Id);
IsLoading = false;
}
}