<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def attached_to_model(self):
 """Tells if the current index is the one attached to the model field, not instance field"""

        try:
            if not bool(self.model):
                return False
        except AttributeError:
            return False
        else:
            try:
                return not bool(self.instance)
            except AttributeError:
                return True