parameters: (self, streetlearn)
docstring: Color panos along the current shortest path to the current target.
  
      Args:
        streetlearn: the streetlearn environment.
docstring_summary: Color panos along the current shortest path to the current target.
docstring_tokens: Color panos along the current shortest path to the current target .
function: def _color_shortest_path(self, streetlearn):
      """Color panos along the current shortest path to the current target.
  
      Args:
        streetlearn: the streetlearn environment.
      """
      for pano_id in self._shortest_path:
        self._pano_id_to_color.setdefault(pano_id, self._colors['shortest_path'])
function_tokens: def _color_shortest_path ( self , streetlearn ) : for pano_id in self . _shortest_path : self . _pano_id_to_color . setdefault ( pano_id , self . _colors [ 'shortest_path' ] )