function decodeCoordString(coord_string, place) {
  let coord_strings = coord_string.split(","),
    lat_lng = L.latLng(coord_strings);
  lat_lng.new_place = place;

  return lat_lng;
}
Turn a string containing coordinates (a graph node's ID) into a LatLng object.
@private

@param {string} coord_string - A string containing coordinates in the format of "Latitude,Longitude".
@param {object} place - An object specifying the place of the coordinate string.
@returns {LatLng} - The coordinates encoded by the coord_string.