code: def test_multiple_enterable(self):
      cm = mlmd_cm.MLMDConnectionManager.fake()
      with cm:
          with cm:
              m1 = cm.primary_mlmd_handle
          m2 = cm.primary_mlmd_handle
          self.assertIs(m1, m2)
      with self.assertRaises(RuntimeError):
          cm.primary_mlmd_handle
  
file_path: tfx/tfx/orchestration/mlmd_connection_manager_test.py
imports: from unittest import mock
  import tensorflow
  from tfx.orchestration import mlmd_connection_manager
  import ml_metadata
label_desc: Use image node_id 5 for calling the MlmdConnectionManagerTest obj's underlying member method code with example usage: obj.test_multiple_enterable() without return types