default ExtendedCell deepClone() {
    // When being added to the memstore, deepClone() is called and KeyValue has less heap overhead.
    return new KeyValue(this);
  }
Does a deep copy of the contents to a new memory area and returns it as a new cell.
@return The deep cloned cell
hbase-common/src/main/java/org/apache/hadoop/hbase/ExtendedCell.java