code: def find_py_files() -> Sequence[Path]:
      """
      Find all ``.py`` files of the GPflow user-facing code.
      """
      root_module = gpflow
      root_path_str = root_module.__file__
      assert root_path_str is not None
      root_path = Path(root_path_str).parent
      return tuple(root_path.glob("**/*.py"))
  
imports: import ast
  from pathlib import Path
  from typing import List, Sequence, Union
  import pytest
  import gpflow
label_desc: Use image node_id 1 for calling a global function with example usage: find_py_files() and returns: tuple