code: function truncateObj(obj, level) {
    var dst = {};
    for (var attr in obj) {
      if (Object.prototype.hasOwnProperty.call(obj, attr)) {
        dst[attr] = module.exports.truncate(obj[attr], level);
      }
    }
  
    return dst;
  }
docs: truncateObj truncates each key in the object separately, which is useful for handling circular references.