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