docs: def get_other_keys(self, key, including_current=False):
          """ Returns list of other keys that are mapped to the same value as specified key. 
              @param key - key for which other keys should be returned.
              @param including_current if set to True - key will also appear on this list."""
          other_keys = []
          if key in self:
              other_keys.extend(self.__dict__[str(type(key))][key])
              if not including_current:
                  other_keys.remove(key)
          return other_keys