code: def parse_message(self, tup_tree):
          
  
          self.check_node(tup_tree, 'MESSAGE', ('ID', 'PROTOCOLVERSION'))
  
          child = self.one_child(tup_tree,
                                 ('SIMPLEREQ', 'MULTIREQ', 'SIMPLERSP',
                                  'MULTIRSP', 'SIMPLEEXPREQ', 'MULTIEXPREQ',
                                  'SIMPLEEXPRSP', 'MULTIEXPRSP'))
  
          return name(tup_tree), attrs(tup_tree), child
docs: ::
  
              <!ELEMENT MESSAGE (SIMPLEREQ | MULTIREQ | SIMPLERSP | MULTIRSP |
                                 SIMPLEEXPREQ | MULTIEXPREQ | SIMPLEEXPRSP |
                                 MULTIEXPRSP)
              <!ATTLIST MESSAGE
                  ID CDATA #REQUIRED
                  PROTOCOLVERSION CDATA #REQUIRED>