parseManifest(manifestXml) {
    var manifest = {}; //-- Turn items into an array
    // var selected = manifestXml.querySelectorAll("item");

    var selected = Object(core["qsa"])(manifestXml, "item");
    var items = Array.prototype.slice.call(selected); //-- Create an object with the id as key

    items.forEach(function (item) {
      var id = item.getAttribute("id"),
          href = item.getAttribute("href") || "",
          type = item.getAttribute("media-type") || "",
          overlay = item.getAttribute("media-overlay") || "",
          properties = item.getAttribute("properties") || "";
      manifest[id] = {
        "href": href,
        // "url" : href,
        "type": type,
        "overlay": overlay,
        "properties": properties.length ? properties.split(" ") : []
      };
    });
    return manifest;
  }
Parse Manifest
@private
@param  {node} manifestXml
@return {object} manifest