code: def test_is_closed(self):
      client = SparkConnectClient(
          "sc://foo/;token=bar", use_reattachable_execute=False
      )
  
      self.assertFalse(client.is_closed)
      client.close()
      self.assertTrue(client.is_closed)
  
imports: import unittest
  import uuid
  from collections.abc import Generator
  from typing import Optional, Any
  from pyspark.testing.connectutils import should_test_connect, connect_requirement_message
  from pyspark.testing.utils import eventually
label_desc: Use image node_id 6 for calling the SparkConnectClientTestCase obj's underlying member method code with example usage: obj.test_is_closed() without return types