code: function sample(test, asap, minDuration, sampleSize, done) {
      var count = 0;
      var totalDuration = 0;
      var sampleDurations = [];
      next();
      function next() {
          measure(function (done) {
              test(asap, done);
          }, function (error, results, duration) {
              if (error) {
                  done(error);
              }
              if (sampleDurations.length < sampleSize) {
                  sampleDurations.push(duration);
              } else if (Math.random() < 1 / count) {
                  sampleDurations.splice(Math.floor(Math.random() * sampleDurations.length), 1);
                  sampleDurations.push(duration);
              }
              totalDuration += duration;
              count++;
              if (totalDuration >= minDuration) {
                  done(null, {
                      name: test.name,
                      subjectName: asap.name,
                      count: count,
                      totalDuration: totalDuration,
                      averageFrequency: count / totalDuration,
                      averageDuration: totalDuration / count,
                      averageOpsHz: count / totalDuration,
                      sampleDurations: sampleDurations
                  });
              } else {
                  next();
              }
          });
      }
  }
docs: measures iterations of the test for a duration, maintaining a representative sample of the measurements up to a given size