code: def test_complete_subcommands(self, argcomplete_on):
      app = MainApp()
      assert set(self.run_completer(app, "app ")) >= {
          "subapp1",
          "subapp2",
      }
      assert set(self.run_completer(app, "app sub")) == {
          "subapp1",
          "subapp2",
      }
      assert set(self.run_completer(app, "app subapp1")) == {"subapp1"}
  
imports: import io
  import os
  import typing
  import pytest
  from traitlets import Unicode
  from traitlets.config.application import Application
  from traitlets.config.configurable import Configurable
  from traitlets.config.loader import KVArgParseConfigLoader
label_desc: Use image node_id 5 for calling the TestArgcomplete obj's underlying member method code with example usage: obj.test_complete_subcommands(argcomplete_on) without return types