code: def test_get_default_connector(self):
      folder = tempfile.mkdtemp()
      env_file = os.path.join(folder, "env.ini")
      with open(env_file, "w") as f:
          f.write("[Auptimizer]\n")
      self.assertRaises(KeyError, utils.get_default_connector, folder)
      with open(env_file, "w") as f:
          f.write("[Auptimizer]\nSQL_ENGINE = wrong")
      self.assertRaises(KeyError, utils.get_default_connector, folder)
      with open(env_file, "w") as f:
          f.write("[Auptimizer]\nSQL_ENGINE = sqlite")
      self.assertRaises(KeyError, utils.get_default_connector, folder)
      os.remove(env_file)
      os.rmdir(folder)
  
file_path: auptimizer/tests/test_utils.py
imports: import unittest
  import os
  import sys
  from six import StringIO
  from aup import utils
  import tempfile
label_desc: Use image node_id 2 for calling the UtilTestCase obj's underlying member method code with example usage: obj.test_get_default_connector() without return types