@Override
    long sizeOfByteArray(int len) {
      return align(ARRAY + len * ARRAY_BYTE_INDEX_SCALE);
    }
UnsafeLayout uses Unsafe to guesstimate the object-layout related parameters like object header
sizes and oop sizes See HBASE-15950.
hbase-common/src/main/java/org/apache/hadoop/hbase/util/ClassSize.java