code: def resolve_namespace(self, qname):
          
          if ':' in qname:
              prefix, name = qname.split(':', 1)
              uri = self._ns[prefix]
          else:
              name = qname
              if None in self._ns:
                  uri = self._ns[None]
              else:
                  uri = None
          return (uri, name)
docs: Obtain (uri, name) from a qualified name