function PerformanceWatchdog(options) {
  //>>includeStart('debug', pragmas.debug);
  if (!defined(options) || !defined(options.container)) {
    throw new DeveloperError("options.container is required.");
  }
  if (!defined(options.scene)) {
    throw new DeveloperError("options.scene is required.");
  }
  //>>includeEnd('debug');

  const container = getElement(options.container);

  const viewModel = new PerformanceWatchdogViewModel(options);

  const element = document.createElement("div");
  element.className = "cesium-performance-watchdog-message-area";
  element.setAttribute("data-bind", "visible: showingLowFrameRateMessage");

  const dismissButton = document.createElement("button");
  dismissButton.setAttribute("type", "button");
  dismissButton.className = "cesium-performance-watchdog-message-dismiss";
  dismissButton.innerHTML = "&times;";
  dismissButton.setAttribute("data-bind", "click: dismissMessage");
  element.appendChild(dismissButton);

  const message = document.createElement("div");
  message.className = "cesium-performance-watchdog-message";
  message.setAttribute("data-bind", "html: lowFrameRateMessage");
  element.appendChild(message);

  container.appendChild(element);

  knockout.applyBindings(viewModel, element);

  this._container = container;
  this._viewModel = viewModel;
  this._element = element;
}
Monitors performance of the application and displays a message if poor performance is detected.

@alias PerformanceWatchdog
@constructor

@param {object} [options] Object with the following properties:
@param {Element|string} options.container The DOM element or ID that will contain the widget.
@param {Scene} options.scene The {@link Scene} for which to monitor performance.
@param {string} [options.lowFrameRateMessage='This application appears to be performing poorly on your system.  Please try using a different web browser or updating your video drivers.'] The
       message to display when a low frame rate is detected.  The message is interpeted as HTML, so make sure
       it comes from a trusted source so that your application is not vulnerable to cross-site scripting attacks.