code: def test_constant(self):
      gateway = get_gateway()
      JExecutionConfig = (
          gateway.jvm.org.apache.flink.api.common.ExecutionConfig
      )
  
      self.assertEqual(
          ExecutionConfig.PARALLELISM_DEFAULT,
          JExecutionConfig.PARALLELISM_DEFAULT,
      )
      self.assertEqual(
          ExecutionConfig.PARALLELISM_UNKNOWN,
          JExecutionConfig.PARALLELISM_UNKNOWN,
      )
  
imports: from pyflink.datastream import StreamExecutionEnvironment
  from pyflink.common import ExecutionConfig, RestartStrategies, ExecutionMode, Configuration
  from pyflink.java_gateway import get_gateway
  from pyflink.testing.test_case_utils import PyFlinkTestCase
  from pyflink.util.java_utils import get_j_env_configuration
label_desc: Use image node_id 2 for calling the ExecutionConfigTests obj's underlying member method code with example usage: obj.test_constant() without return types