code: def isID(self, elem, attr):
          
          if elem is None: elem__o = None
          else: elem__o = elem._o
          if attr is None: attr__o = None
          else: attr__o = attr._o
          ret = libxml2mod.xmlIsID(self._o, elem__o, attr__o)
          return ret
docs: Determine whether an attribute is of type ID. In case we
            have DTD(s) then this is done if DTD loading has been
            requested. In the case of HTML documents parsed with the
             HTML parser, then ID detection is done systematically.