unittest.TestSuite() right-click运行出现错误：触发所有测试用例而不是仅触发指定的test_case1

    import requests
    import unittest
    
    class unit_test_3(unittest.TestCase):
    def setUp(self):
        print(44)
    def test_1_register(self):
        print(1)
    def test_2_login(self):
        print(2)
    def tearDown(self):
        print(55)
    if __name__ == '__main__':
    #创建测试套件对象
    suite1 = unittest.TestSuite()
    #把测试用例加进测试套件
    suite1.addTest(unit_test_3("test_1_register"))
    #声明框架的运行对象
    runner = unittest.TextTestRunner()
    #runner对象调用run方法，执行测试套件
    runner.run(suite1)