code: public long lowestEquivalentValue(final long value) {
          final int bucketIndex = getBucketIndex(value);
          final int subBucketIndex = getSubBucketIndex(value, bucketIndex);
          long thisValueBaseLevel = valueFromIndex(bucketIndex, subBucketIndex);
          return thisValueBaseLevel;
      }
docs: Get the lowest value that is equivalent to the given value within the histogram's resolution.
  Where "equivalent" means that value samples recorded for any two
  equivalent values are counted in a common total count.
  
  @param value The given value
  @return The lowest value that is equivalent to the given value within the histogram's resolution.