docs: function findElementAttributeValue(attributeName, elems) {
  
      elems = Array.isArray(elems) ? elems : [ elems ];
  
      var value = elems.filter(function (elem) {
          return elem.attrib.name.toLowerCase() === attributeName.toLowerCase();
      }).map(function (filteredElems) {
          return filteredElems.attrib.value;
      }).pop();
  
      return value ? value : '';
  }