public ObservableCollection <CustomerBaseRepresentation> GetContacts(CustomerBaseRepresentation firm)
{
using (ISQLConnection dataSource = DataSource)
{
List <Customers> contactList = dataSource.GetContacts(RepresentationConverter.convertCustomer(firm));
List <CustomerBaseRepresentation> contactListRep = contactList.Select(c => RepresentationConverter.convertCustomer(c)).ToList();
return(new ObservableCollection <CustomerBaseRepresentation>(contactListRep));
}
}