code: function on(type, listener) {
        var object = this,
            events = object.events || (object.events = {});
  
        _.each(type.split(' '), function(type) {
          (_.has(events, type)
            ? events[type]
            : (events[type] = [])
          ).push(listener);
        });
        return object;
      }
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 current 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);