code: def parse_returnvalue(self, tup_tree):
          
  
          # Version 2.1.1 of the DTD lacks the %ParamType attribute but it
          # is present in version 2.2.  Make it optional to be backwards
          # compatible.
  
          self.check_node(tup_tree, 'RETURNVALUE', (),
                          ('PARAMTYPE', 'EmbeddedObject', 'EMBEDDEDOBJECT'))
  
          child = self.optional_child(tup_tree, ('VALUE', 'VALUE.REFERENCE'))
          attrl = attrs(tup_tree)
  
          if 'EmbeddedObject' in attrl or 'EMBEDDEDOBJECT' in attrl:
              child = self.parse_embeddedObject(child)
  
          return name(tup_tree), attrl, child
docs: Parse the RETURNVALUE element. Returns name, attributes, and
          one child as a tuple.
  
            ::
  
              <!ELEMENT RETURNVALUE (VALUE | VALUE.REFERENCE)?>
              <!ATTLIST RETURNVALUE
                  %EmbeddedObject;
                  %ParamType;       #IMPLIED>