constructor(x, y) {
        /**
         * The point's x coordinate.
         * @type {!number}
         */
        this.x = x;
        /**
         * The point's y coordinate.
         * @member Point#y
         * @type {!number}
         */
        this.y = y;
    }
@param {!number} x The new point's x coordinate.
@param {!number} y The new point's y coordinate.