code: def _test() -> None:
      import doctest
      import sys
      from pyspark import SparkContext
  
      globs = globals().copy()
      globs["sc"] = SparkContext("local[2]", "files tests")
      (failure_count, test_count) = doctest.testmod(
          globs=globs, optionflags=doctest.ELLIPSIS
      )
      globs["sc"].stop()
      if failure_count:
          sys.exit(-1)
  
imports: import os
  from typing import cast, ClassVar, Optional, TYPE_CHECKING
label_desc: Use image node_id 1 for calling a global function with example usage: _test() without return types