code: def _fixNS(self, namespace):
          
          if namespace == OPENID_NS:
              if self._openid_ns_uri is None:
                  raise UndefinedOpenIDNamespace('OpenID namespace not set')
              else:
                  namespace = self._openid_ns_uri
  
          if namespace != BARE_NS and type(namespace) not in [str, unicode]:
              raise TypeError(
                  "Namespace must be BARE_NS, OPENID_NS or a string. got %r"
                  % (namespace,))
  
          if namespace != BARE_NS and ':' not in namespace:
              fmt = 'OpenID 2.0 namespace identifiers SHOULD be URIs. Got %r'
              warnings.warn(fmt % (namespace,), DeprecationWarning)
  
              if namespace == 'sreg':
                  fmt = 'Using %r instead of "sreg" as namespace'
                  warnings.warn(fmt % (SREG_URI,), DeprecationWarning,)
                  return SREG_URI
  
          return namespace
docs: Convert an input value into the internally used values of
          this object
  
          @param namespace: The string or constant to convert
          @type namespace: str or unicode or BARE_NS or OPENID_NS