code: def test_package(self):
      source = self.main_in_children_source
      with os_helper.temp_dir() as script_dir:
          pkg_dir = os.path.join(script_dir, "test_pkg")
          make_pkg(pkg_dir)
          script_name = _make_test_script(
              pkg_dir, "__main__", source=source
          )
          launch_name = _make_launch_script(
              script_dir, "launch", "test_pkg"
          )
          self._check_script(launch_name)
  
imports: from test import support
  from test.support import import_helper
  import importlib
  import importlib.machinery
  import unittest
  import sys
  import os
  import os.path
  import py_compile
  from test.support import os_helper
  from test.support.script_helper import make_pkg, make_script, make_zip_pkg, make_zip_script, assert_python_ok
  import multiprocessing
label_desc: Use image node_id 15 for calling the MultiProcessingCmdLineMixin obj's underlying member method code with example usage: obj.test_package() without return types