constructor(x, y, w, h, id) {
    this.id = id;

    /** @type {number} */
    this.left = x;

    /** @type {number} */
    this.top = y;

    /** @type {number} */
    this.width = w;

    /** @type {number} */
    this.height = h;
  }
Class for representing rectangular regions.
https://github.com/google/closure-library/blob/master/closure/goog/math/rect.js
@param {number} x Left.
@param {number} y Top.
@param {number} w Width.
@param {number} h Height.
@param {number} id Identifier
@constructor