code: function _ioSuccess(o, c) {
          var a = c.arguments;
  
          if (a) {
              Y.fire(E_SUCCESS, o.id, o.c, a);
          }
          else {
              Y.fire(E_SUCCESS, o.id, o.c);
          }
  
          if (c.on && c.on.success) {
              _tE('success', c).fire(o.id, o.c);
          }
  
          _ioEnd(o, c);
      }
docs: @description Fires event "io:success" and creates, fires a
  transaction-specific "success" event, if config.on.success is
  defined.
  
  @method _ioSuccess
  @private
  @static
  @param {object} o - transaction object.
  @param {object} c - configuration object for the transaction.
  
  @return void