code: function ReadWrite(properties) {
                          if (properties)
                              for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
                                  if (properties[keys[i]] != null)
                                      this[keys[i]] = properties[keys[i]];
                      }
docs: Properties of a ReadWrite.
  @memberof google.firestore.v1.TransactionOptions
  @interface IReadWrite
  @property {Uint8Array|null} [retryTransaction] ReadWrite retryTransaction
   
  Constructs a new ReadWrite.
  @memberof google.firestore.v1.TransactionOptions
  @classdesc Represents a ReadWrite.
  @implements IReadWrite
  @constructor
  @param {google.firestore.v1.TransactionOptions.IReadWrite=} [properties] Properties to set