createTransitLayer(options) {
        return this._map.then((map) => {
            let newLayer = new google.maps.TransitLayer();
            newLayer.setMap(options.visible ? map : null);
            return newLayer;
        });
    }
/**
     * Creates a TransitLayer instance for a map
     * @param {TransitLayerOptions} options - used for setting layer options
     * @returns {Promise<TransitLayer>} a new transit layer object
     */
Creates a TransitLayer instance for a map
@param {TransitLayerOptions} options - used for setting layer options
@returns {Promise} a new transit layer object
Creates a TransitLayer instance for a map @param { TransitLayerOptions } options - used for setting layer options @returns { Promise } a new transit layer object
createTransitLayer(options) {
        return this._map.then((map) => {
            let newLayer = new google.maps.TransitLayer();
            newLayer.setMap(options.visible ? map : null);
            return newLayer;
        });
    }
createTransitLayer ( options ) { return this . _map . then ( ( map ) => { let newLayer = new google . maps . TransitLayer ( ) ; newLayer . setMap ( options . visible ? map : null ) ; return newLayer ; } ) ; }
Creates a TransitLayer instance for a map
 @param {TransitLayerOptions} options - used for setting layer options
 @returns {Promise<TransitLayer>} a new transit layer object
Creates a TransitLayer instance for a map @param { TransitLayerOptions } options - used for setting layer options @returns { Promise<TransitLayer > } a new transit layer object