/**
     * Manually add an item to the uploading queue.
     *
     * @param {PIXI.DisplayObject|PIXI.Container|PIXI.BaseTexture|PIXI.Texture|PIXI.Graphics|PIXI.Text|*} item - Object to
     *        add to the queue
     * @return {PIXI.CanvasPrepare} Instance of plugin for chaining.
     */