code: function run (N, op, init) {
    var stats = null, value
    for(var j = 0; j < 100; j++) {
      if(init) value = init(j)
      var start = Date.now()
      for(var i = 0; i < N; i++) op(value, i)
      stats = Stats(stats, N/((Date.now() - start)))
    }
    return stats
  }
docs: simple benchmarks, and measure standard deviation