TypeScript: Possibly wrong typing of IsoSprite.isoBounds

[CubixSystem]

I met this error error TS2339: Property 'containsXY' does not exist on type 'Point3'. with my code

isoGroup: Phaser.Group;
...
this.isoGroup.forEach((tile: Phaser.Plugin.Isometric.IsoSprite) => {
    let inBounds: boolean = tile.isoBounds.containsXY(
    this.cursorPos.x,
    this.cursorPos.y
);

I found this lines of code in in phaser.plugin.isometric package
phaser.plugin.isometric.d.ts:

class IsoSprite extends Phaser.Sprite {
    ...
    isoBounds: Phaser.Plugin.Isometric.Point3;
    ...
}

But in phaser-plugin-isometric.js:

Phaser.Plugin.Isometric.IsoSprite.prototype.resetIsoBounds = function () {
    if (typeof this._isoBounds === "undefined") {
        this._isoBounds = new Phaser.Plugin.Isometric.Cube();
    }
    ...
};

In runtime console.log of any Phaser.Plugin.Isometric.IsoSprite instance shown that it has in __proto__ key isoBounds with instance of Phaser.Plugin.Isometric.Cube as a value