function _ResizeObserverSPI(callback, controller, callbackCtx) {
    /**
     * Collection of resize observations that have detected changes in dimensions
     * of elements.
     *
     * @private {Array<ResizeObservation>}
     */
    this.activeObservations_ = []
    /**
     * Registry of the ResizeObservation instances.
     *
     * @private {Map<Element, ResizeObservation>}
     */

    this.observations_ = new MapShim()

    if (typeof callback !== 'function') {
      throw new TypeError(
        'The callback provided as parameter 1 is not a function.'
      )
    }

    this.callback_ = callback
    this.controller_ = controller
    this.callbackCtx_ = callbackCtx
  }
/**
   * Creates a new instance of ResizeObserver.
   *
   * @param {ResizeObserverCallback} callback - Callback function that is invoked
   *      when one of the observed elements changes it's content dimensions.
   * @param {ResizeObserverController} controller - Controller instance which
   *      is responsible for the updates of observer.
   * @param {ResizeObserver} callbackCtx - Reference to the public
   *      ResizeObserver instance which will be passed to callback function.
   */
Creates a new instance of ResizeObserver.
@param {ResizeObserverCallback} callback - Callback function that is invoked
when one of the observed elements changes it's content dimensions.
@param {ResizeObserverController} controller - Controller instance which
is responsible for the updates of observer.
@param {ResizeObserver} callbackCtx - Reference to the public
ResizeObserver instance which will be passed to callback function.
Creates a new instance of ResizeObserver . @param { ResizeObserverCallback } callback - Callback function that is invoked when one of the observed elements changes it ' s content dimensions . @param { ResizeObserverController } controller - Controller instance which is responsible for the updates of observer . @param { ResizeObserver } callbackCtx - Reference to the public ResizeObserver instance which will be passed to callback function .
function _ResizeObserverSPI(callback, controller, callbackCtx) {
    this.activeObservations_ = []
    this.observations_ = new MapShim()
    if (typeof callback !== 'function') {
      throw new TypeError(
        'The callback provided as parameter 1 is not a function.'
      )
    }
    this.callback_ = callback
    this.controller_ = controller
    this.callbackCtx_ = callbackCtx
  }
function _ResizeObserverSPI ( callback , controller , callbackCtx ) { this . activeObservations_ = [ ] this . observations_ = new MapShim ( ) if ( typeof callback !== 'function' ) { throw new TypeError ( 'The callback provided as parameter 1 is not a function.' ) } this . callback_ = callback this . controller_ = controller this . callbackCtx_ = callbackCtx }
Creates a new instance of ResizeObserver.
Creates a new instance of ResizeObserver .
/**
     * Collection of resize observations that have detected changes in dimensions
     * of elements.
     *
     * @private {Array<ResizeObservation>}
     */ /**
     * Registry of the ResizeObservation instances.
     *
     * @private {Map<Element, ResizeObservation>}
     */