docs: def name_for_callable(func):
    """Returns a module name for a callable or `None` if no name can be found."""
    if isinstance(func, functools.partial):
      return name_for_callable(func.func)
  
    try:
      name = func.__name__
    except AttributeError:
      return None
  
    if name == "<lambda>":
      return None
    else:
      return to_snake_case(name)