How to write a test case for inherited class

I have a methond blah for which I want to write test case. The class is :

class TEST_ME(UPPERCLASS):
      def __init__(self):
            super(TEST_ME, self).__init__()
      def blah(self):
             .

.

The UPPERCLASS is:
class UPPERCLASS:
      def __init__(self):
          self.configuration = get_configurations()
          self.session = get_session(self.configuration.AIRFLOW_URL)

Now I am trying to write TEST CASE for TEST_ME :

def test_blah(mocked_config, testing_session):
     TEST_ME_obj = TEST_ME()

But this throws me error since it does not pick mocked_config. can someone help