code: def test_flatten() -> None:
      out = tools.flatten(["a", {"truc": [4, 5]}])
      assert out == {"0": "a", "1.truc.0": 4, "1.truc.1": 5}
  
file_path: nevergrad/nevergrad/common/test_tools.py
imports: import os
  import typing
  import numpy
  from .None import tools
  from .None import testing
label_desc: Use image node_id 7 for calling a global function with example usage: test_flatten() without return types