code: def process_attribute(self, type_, attr, value, level):
          
  
          attr_props = self.get_attribute_properties(type_, attr)
          value = self.format_value(attr, attr_props, value)
          line = self.__format_line(self.whitespace(level, 1), attr.upper(), value)
  
          return line
docs: Process one of the main composite types (see the type_ value)