code: def categories(self, value):
          
  
          if value is not None:
              assert type(value) is dict, "'{0}' attribute: '{1}' type is not 'dict'!".format("categories", value)
              for key, element in value.iteritems():
                  assert type(key) is dict, "'{0}' attribute: '{1}' type is not 'dict'!".format("categories", key)
                  assert type(element) is list, "'{0}' attribute: '{1}' type is not 'list'!".format(
                      "categories", element)
          self.__categories = value
docs: Setter for **self.__categories** attribute.
  
          :param value: Attribute value.
          :type value: dict