'od.__delitem__(y) <==> del od[y]'

def __delitem__(self, key, dict_delitem=dict.__delitem__):

    dict_delitem(self, key)
    link = self.__map.pop(key)
    link_prev = link.prev
    link_next = link.next
    link_prev.next = link_next
    link_next.prev = link_prev
