code: def add_path_segment(self, value):
          
          segments = self.path_segments() + (to_unicode(value),)
          return self.path_segments(segments)
docs: Add a new path segment to the end of the current string
  
          :param string value: the new path segment to use
  
          Example::
  
              >>> u = URL('http://example.com/foo/')
              >>> u.add_path_segment('bar').as_string()
              'http://example.com/foo/bar'