code: def test_create_jobmanager_checkpoint_storage(self):
      self.assertIsNotNone(JobManagerCheckpointStorage())
  
      self.assertIsNotNone(
          JobManagerCheckpointStorage("file://var/checkpoints/")
      )
  
      self.assertIsNotNone(
          JobManagerCheckpointStorage(
              "file://var/checkpoints/", 10000000
          )
      )
  
file_path: flink/flink-python/pyflink/datastream/tests/test_checkpoint_storage.py
imports: from pyflink.datastream.checkpoint_storage import JobManagerCheckpointStorage, FileSystemCheckpointStorage
  from pyflink.java_gateway import get_gateway
  from pyflink.testing.test_case_utils import PyFlinkTestCase
label_desc: Use image node_id 2 for calling the JobManagerCheckpointStorageTests obj's underlying member method code with example usage: obj.test_create_jobmanager_checkpoint_storage() without return types