code: def test_import_string(self):
      cls = import_string("airflow.utils.module_loading.import_string")
      assert cls == import_string
  
      # Test exceptions raised
      with pytest.raises(ImportError):
          import_string("no_dots_in_path")
      msg = 'Module "airflow.utils" does not define a "nonexistent" attribute'
      with pytest.raises(ImportError, match=msg):
          import_string("airflow.utils.nonexistent")
  
imports: from __future__ import annotations
  import pytest
  from airflow.utils.module_loading import import_string
label_desc: Use image node_id 1 for calling the TestModuleImport obj's underlying member method code with example usage: obj.test_import_string() without return types