code: def dummy_table():
      if Env._dummy_table is None:
          import hail
  
          Env._dummy_table = (
              hail.utils.range_table(1, 1).key_by().cache()
          )
      return Env._dummy_table
  
imports: from typing import Optional, Union
  import sys
  import re
  from hailtop.config import ConfigVariable, configuration_of
label_desc: Use image node_id 10 for calling the Env obj's underlying member method code with example usage: obj.dummy_table() and returns: Env