code: function wrap(obj, opts) {
    var result = {};
    for (var key in obj) {
      if(obj.hasOwnProperty(key)) {
        var wrapped = wrap1(obj[key], opts, key);
        if (typeof wrapped !== 'undefined')
          result[key] = wrapped;
      }
    }
    return result;
  }
docs: Wrap object properties into DynamoDB's AttributeValue data type.
  @param {Object} obj The object to wrap.
  @return {Object} A DynamoDb AttributeValue.