//this makes sure that
private static void EnsureCallbackForIContactsDataServiceIsCalled(IContactsDataService contactsDataService,
Action <IContactsDataService> methodToReturnTheData, List <Contact> mockContactData, Func <object[], object> getCallbackFromArguments)
{
var actionOnGetContacts = getCallbackFromArguments(contactsDataService.GetArgumentsForCallsMadeOn(methodToReturnTheData).First());
((Action <IEnumerable <Contact> >)actionOnGetContacts).Invoke(mockContactData);
}
