function compareIndexesFirst(a, b)
        {
            var index1 = toArrayIndex(a.name);
            var index2 = toArrayIndex(b.name);
            if (index1 < 0)
                return index2 < 0 ? 0 : 1;
            return index2 < 0 ? -1 : index1 - index2;
        }
@param {!RuntimeAgent.PropertyPreview} a
@param {!RuntimeAgent.PropertyPreview} b