@Override
  public ExtendedCell deepClone() {
    byte[] copy = new byte[this.length];
    ByteBufferUtils.copyFromBufferToArray(copy, this.buf, this.offset, 0, this.length);
    KeyValue kv = new KeyValue(copy, 0, copy.length);
    kv.setSequenceId(this.getSequenceId());
    return kv;
  }
This Cell is an implementation of {@link ByteBufferExtendedCell} where the data resides in off
heap/ on heap ByteBuffer
hbase-common/src/main/java/org/apache/hadoop/hbase/ByteBufferKeyValue.java