code: def margin(self, value):
          
  
          if value is not None:
              assert type(value) is int, "'{0}' attribute: '{1}' type is not 'int'!".format("margin", value)
              assert value > 0, "'{0}' attribute: '{1}' need to be exactly positive!".format("margin", value)
          self.__margin = value
docs: Setter for **self.__margin** attribute.
  
          :param value: Attribute value.
          :type value: int