function AbstractMediaLoader(loadItem, preferXHR, type) {
		this.AbstractLoader_constructor(loadItem, preferXHR, type);

		// public properties
		this.resultFormatter = this._formatResult;

		// protected properties
		this._tagSrcAttribute = "src";

        this.on("initialize", this._updateXHR, this);
	}
The AbstractMediaLoader is a base class that handles some of the shared methods and properties of loaders that
handle HTML media elements, such as Video and Audio.
@class AbstractMediaLoader
@param {LoadItem|Object} loadItem
@param {Boolean} preferXHR
@param {String} type The type of media to load. Usually "video" or "audio".
@extends AbstractLoader
@constructor