code: def match(self, name=None, ns=None):
          
          if name is None:
              byname = True
          else:
              byname = self.name == name
          if ns is None:
              byns = True
          else:
              byns = self.namespace()[1] == ns[1]
          return byname and byns
docs: Match by (optional) name and/or (optional) namespace.
          @param name: The optional attribute tag name.
          @type name: str
          @param ns: An optional namespace.
          @type ns: (I{prefix}, I{name})
          @return: True if matched.
          @rtype: boolean