public void setKey(ByteBuffer key, int offset, int length) {
    setKey(key, offset, length, ByteBufferUtils.toShort(key, offset));
  }
A setter that helps to avoid object creation every time and whenever there is a need to create
new OffheapKeyOnlyKeyValue.
hbase-common/src/main/java/org/apache/hadoop/hbase/ByteBufferKeyOnlyKeyValue.java