code: def _warn_obsolete_waypoints():
      warnings.warn(
          'Passing "None" to waypoints is deprecated, and will be '
          "removed in jupyter-gmaps 0.9.0. "
          "Pass an empty list.",
          DeprecationWarning,
      )
  
file_path: gmaps/gmaps/directions.py
imports: import ipywidgets
  import warnings
  from traitlets import Bool, Unicode, CUnicode, List, Enum, observe, validate, Float
  from .None import geotraitlets
  from .maps import GMapsWidgetMixin
  from ._docutils import doc_subst
label_desc: Use image node_id 2 for calling a global function with example usage: _warn_obsolete_waypoints() without return types