code: def get(self, value):
          
          _nothing = object()
          item = self._values.get(value, _nothing)
          if item is _nothing:
              raise InvalidEnumItem(value)
          return item
docs: Get an enumeration item for an enumeration value.
  
          :param unicode value: Enumeration value.
          :raise InvalidEnumItem: If ``value`` does not match any known
          enumeration value.
          :rtype: EnumItem