plugin/boomerang/boomerang-1.0.0.js
/**
	 * Collect external resources by tagName
	 *
	 * @param {Element} a an anchor element
	 * @param {Object} obj object of resources where the key is the url
	 * @param {string} tagName tag name to collect
	 */
Collect external resources by tagName
@param {Element} a an anchor element
@param {Object} obj object of resources where the key is the url
@param {string} tagName tag name to collect
Collect external resources by tagName @param { Element } a an anchor element @param { Object } obj object of resources where the key is the url @param { string } tagName tag name to collect
function collectResources(a, obj, tagName) {
		Array.prototype
			.forEach
			.call(a.ownerDocument.getElementsByTagName(tagName), function(r) {
				a.href = r.currentSrc ||
					r.src ||
					(typeof r.getAttribute === "function" && r.getAttribute("xlink:href")) ||
					r.href;
				if (a.href.match(/^https?:\/\//)) {
					obj[a.href] = r;
				}
			});
	}
function collectResources ( a , obj , tagName ) { Array . prototype . forEach . call ( a . ownerDocument . getElementsByTagName ( tagName ) , function ( r ) { a . href = r . currentSrc || r . src || ( typeof r . getAttribute === "function" && r . getAttribute ( "xlink:href" ) ) || r . href ; if ( a . href . match ( / ^https?:\/\/ / ) ) { obj [ a . href ] = r ; } } ) ; }
Collect external resources by tagName
 @param {Element} a an anchor element
 @param {Object} obj object of resources where the key is the url
 @param {string} tagName tag name to collect
Collect external resources by tagName @param { Element } a an anchor element @param { Object } obj object of resources where the key is the url @param { string } tagName tag name to collect
// Get canonical URL // only get external resource