constructor({
    div,
    accessibilityManager,
    annotationCanvasMap,
    annotationEditorUIManager,
    page,
    viewport,
    structTreeLayer,
  }) {
    this.div = div;
    this.#accessibilityManager = accessibilityManager;
    this.#annotationCanvasMap = annotationCanvasMap;
    this.#structTreeLayer = structTreeLayer || null;
    this.page = page;
    this.viewport = viewport;
    this.zIndex = 0;
    this._annotationEditorUIManager = annotationEditorUIManager;

    if (typeof PDFJSDev !== "undefined" && PDFJSDev.test("TESTING")) {
      // For testing purposes.
      Object.defineProperty(this, "showPopups", {
        value: async () => {
          for (const show of this.popupShow) {
            await show();
          }
        },
      });
      this.popupShow = [];
    }
  }
Manage the layer containing all the annotations.