code: function on(type, listener) {
      var me = this,
          events = me.events || (me.events = {});
  
      forEach(type.split(' '), function(type) {
        (hasKey(events, type)
          ? events[type]
          : (events[type] = [])
        ).push(listener);
      });
      return me;
    }
docs: Registers a listener for the specified event type(s).
  
  @memberOf Benchmark, Benchmark.Suite
  @param {String} type The event type.
  @param {Function} listener The function to register.
  @returns {Object} The benchmark instance.
  @example
  
  // register a listener for an event type
  bench.on('cycle', listener);
  
  // register a listener for multiple event types
  bench.on('start cycle', listener);