code: function() {
          var ctx = u.context(TINY);
          logger.debugf('Invoke size(msgId=%d)', ctx.id);
          return futureDecodeOnly(ctx, 0x29, p.decodeVInt);
        }
docs: Count of entries in the server(s).
  
  @returns {module:promise.Promise.<Number>}
  A promise that will be completed with the number of entries stored.
  @memberof Client#
  @since 0.3