docs: function rpcCommonNoData(args, callback) {
      assert.func(callback);
      rpcCommonBufferData(args, function (err, data) {
          if (!err && data.length > 0) {
              err = new VError('bad server response: expected 0 data messages, ' +
                  'found %d\n', data.length);
          }
  
          callback(err);
      });
  }