public Delete addFamily(final byte[] family, final long timestamp) {
    checkTimestamp(timestamp);
    List<ExtendedCell> list = getCellList(family);
    if (!list.isEmpty()) {
      list.clear();
    }
    KeyValue kv = new KeyValue(row, family, null, timestamp, KeyValue.Type.DeleteFamily);
    list.add(kv);
    return this;
  }
Delete all columns of the specified family with a timestamp less than or equal to the specified
timestamp.
<p>
Overrides previous calls to deleteColumn and deleteColumns for the specified family.
@param family    family name
@param timestamp maximum version timestamp
@return this for invocation chaining
hbase-client/src/main/java/org/apache/hadoop/hbase/client/Delete.java