_mergeObj = function (to, from) {
  for (var p in from) {
    if (from.hasOwnProperty(p)) {
      to[p] = (typeof from[p] === 'object') ? _mergeObj(to[p], from[p]) : from[p];
    }
  }

  return to;
}
Merge objects
@param  {Object} to
@param  {Object} from
@return {Object}