@Override
  public PositionedByteRange set(byte[] bytes, int offset, int length) {
    this.position = 0;
    super.set(bytes, offset, length);
    limit = length;
    return this;
  }
The current index into the range. Like {@link java.nio.ByteBuffer} position, it points to the
next value that will be read/written in the array. It provides the appearance of being
0-indexed, even though its value is calculated according to offset.
<p>
Position is considered transient and does not participate in {@link #equals(Object)} or
{@link #hashCode()} comparisons.
</p>
hbase-common/src/main/java/org/apache/hadoop/hbase/util/AbstractPositionedByteRange.java