private void primeTracker(Histogram tracker, long numRequests, Pair<Long, Long> latencyRange) {
    for (long i = 0; i < numRequests; i++) {
      // Given latencyRange specifies boundaries of latency: low = latencyRange.getFirst(), high = latencyRange.getSecond().
      // Any randomly generated latency should fall in the range [low, high).
      long latency = Utils.getRandomLong(TestUtils.RANDOM, latencyRange.getSecond() - latencyRange.getFirst())
          + latencyRange.getFirst();
      tracker.update(latency);
    }
  }
Updates the {@code tracker} to mimic {@code numRequests} each taking {@code latency} ms.
@param tracker the {@link Histogram} to update
@param numRequests the number of requests (data points)
@param latencyRange the range of latencies (in ms) to generate and record.
ambry-router/src/test/java/com/github/ambry/router/AdaptiveOperationTrackerTest.java