constructor({ element }) {
    this.element = element;
    this.document = element.ownerDocument;

    // This overlay will be inserted in the document when the mouse moves during
    // a grab operation, to ensure that the cursor has the desired appearance.
    const overlay = (this.overlay = document.createElement("div"));
    overlay.className = "grab-to-pan-grabbing";
  }
Construct a GrabToPan instance for a given HTML element.
@param {GrabToPanOptions} options