public static KeyValue createFirstOnRow(final byte[] row) {
    return createFirstOnRow(row, HConstants.LATEST_TIMESTAMP);
  }
Create a KeyValue that is smaller than all other possible KeyValues for the given row. That is
any (valid) KeyValue on 'row' would sort _after_ the result.
@param row - row key (arbitrary byte array)
@return First possible KeyValue on passed <code>row</code>
hbase-common/src/main/java/org/apache/hadoop/hbase/KeyValueUtil.java