code: def configure_custom(self, config):
          
          c = config.pop('()')
          if not hasattr(c, '__call__') and \
                  hasattr(types, 'ClassType') and isinstance(c, types.ClassType):
              c = self.resolve(c)
          props = config.pop('.', None)
          # Check for valid identifiers
          kwargs = dict((k, config[k]) for k in config if valid_ident(k))
          result = c(**kwargs)
          if props:
              for name, value in props.items():
                  setattr(result, name, value)
          return result
docs: Configure an object with a user-supplied factory.