code: public long getCountBetweenValues(final long lowValue, final long highValue) throws ArrayIndexOutOfBoundsException {
          final int lowIndex = Math.max(0, countsArrayIndex(lowValue));
          final int highIndex = Math.min(countsArrayIndex(highValue), (countsArrayLength - 1));
          long count = 0;
          for (int i = lowIndex ; i <= highIndex; i++) {
              count += getCountAtIndex(i);
          }
          return count;
      }
docs: Get the count of recorded values within a range of value levels (inclusive to within the histogram's resolution).
  
  @param lowValue  The lower value bound on the range for which
  to provide the recorded count. Will be rounded down with
  {@link Histogram#lowestEquivalentValue lowestEquivalentValue}.
  @param highValue  The higher value bound on the range for which to provide the recorded count.
  Will be rounded up with {@link Histogram#highestEquivalentValue highestEquivalentValue}.
  @return the total count of values recorded in the histogram within the value range that is
  {@literal >=} lowestEquivalentValue(<i>lowValue</i>) and {@literal <=} highestEquivalentValue(<i>highValue</i>)