xtuml/meta.py
def compute_index_key(self, to_instance):
        '''
        Compute the index key that can be used to identify an instance
        on the link.
        '''
        kwargs = dict()
        for attr in self.key_map.values():
            if _is_null(to_instance, attr):
                return None
            
            if attr in to_instance.__dict__:
                kwargs[attr] = to_instance.__dict__[attr]
            else:
                kwargs[attr] = getattr(to_instance, attr)

        return frozenset(tuple(kwargs.items()))
def compute_index_key(self, to_instance):
        '''
        Compute the index key that can be used to identify an instance
        on the link.
        '''
        kwargs = dict()
        for attr in self.key_map.values():
            if _is_null(to_instance, attr):
                return None
            
            if attr in to_instance.__dict__:
                kwargs[attr] = to_instance.__dict__[attr]
            else:
                kwargs[attr] = getattr(to_instance, attr)

        return frozenset(tuple(kwargs.items()))
Compute the index key that can be used to identify an instance
        on the link.