code: function getTexture(region) {
           if (_typeof(region) === "object" && typeof region.texture === "string") {
             return this.sources.get(region.texture);
           } else {
             return this.sources.values().next().value;
           }
         }
docs: return the source texture for the given region (or default one if none specified)
  @name getTexture
  @memberOf me.Renderer.Texture
  @function
  @param {Object} [region] region name in case of multipack textures
  @return {HTMLImageElement|HTMLCanvasElement}