displayWindows_(windowsBitmap, pts) {
    // Displays windows from the 8 bit bitmap.
    for (const windowId of this.getSpecifiedWindowIds_(windowsBitmap)) {
      const window = this.windows_[windowId];
      if (!window.isVisible()) {
        // We are turning on the visibility, set the start time.
        window.setStartTime(pts);
      }
      window.display();
    }
  }
@param {number} windowsBitmap
@param {number} pts
@private