code: def test_cli_start_is_fast(testdir: Testdir):
      """
      Checks that a call to ``rasa --help`` does not import any slow imports.
  
      If this is failing this means, that a simple "rasa --help" commands imports
      `tensorflow` which makes our CLI extremely slow. In case this test is failing
      you've very likely added a global import of "tensorflow" which should be
      avoided. Consider making this import (or the import of its parent module)
      a local import.
  
      If you are clueless where that import happens, you can run
      ```
      python -X importtime -m rasa.__main__ --help  2> import.log
      tuna import.log
      ```
      to get the import chain.
      (make sure to run with python >= 3.7, and install tune (pip install tuna))
      """
  
      rasa_path = str(
          (
              Path(__file__).parent
              / ".."
              / ".."
              / "rasa"
              / "__main__.py"
          ).absolute()
      )
      args = [sys.executable, "-X", "importtime", rasa_path, "--help"]
      result = testdir.run(*args)
  
      assert result.ret == 0
  
      # tensorflow is slow -> can't get imported when running basic CLI commands
      result.stderr.no_fnmatch_line("*tensorflow.python.eager")
  
file_path: rasa/tests/cli/test_cli.py
imports: from pathlib import Path
  from typing import Callable
  from pytest import Testdir, RunResult
  import pytest
  import sys
  from tests.cli.conftest import RASA_EXE
label_desc: Use image node_id 1 for calling a global function with example usage: test_cli_start_is_fast(testdir) without return types