'L{server.Session.touch} updates L{server.Session.lastModified} and
delays session timeout.'

def test_touch(self):

    self.clock.advance(3)
    self.session.touch()
    self.assertEqual(self.session.lastModified, 3)
    self.session.startCheckingExpiration()
    self.clock.advance((self.session.sessionTimeout - 1))
    self.session.touch()
    self.clock.advance((self.session.sessionTimeout - 1))
    self.assertIn(self.uid, self.site.sessions)
    self.clock.advance(1)
    self.assertNotIn(self.uid, self.site.sessions)
