def METHOD_NAME(self):
    m = self.get_model()
    m.c = LogicalConstraint(expr=m.a.end_time.at(m.b.start_time, delay=4))
    self.assertIsInstance(m.c.expr, AtExpression)
    self.assertEqual(len(m.c.expr.args), 3)
    self.assertIs(m.c.expr.args[0], m.a.end_time)
    self.assertIs(m.c.expr.args[1], m.b.start_time)
    self.assertEqual(m.c.expr.delay, 4)
    self.assertEqual(str(m.c.expr), "a.end_time + 4 == b.start_time")