public static ExtendedCell createFirstOnRowFamily(Cell cell, byte[] fArray, int foff, int flen) {
    if (cell instanceof ByteBufferExtendedCell) {
      return new FirstOnRowColByteBufferExtendedCell(
        ((ByteBufferExtendedCell) cell).getRowByteBuffer(),
        ((ByteBufferExtendedCell) cell).getRowPosition(), cell.getRowLength(),
        ByteBuffer.wrap(fArray), foff, (byte) flen, HConstants.EMPTY_BYTE_BUFFER, 0, 0);
    }
    return new FirstOnRowColCell(cell.getRowArray(), cell.getRowOffset(), cell.getRowLength(),
      fArray, foff, (byte) flen, HConstants.EMPTY_BYTE_ARRAY, 0, 0);
  }
Create a Cell that is smaller than all other possible Cells for the given Cell's row.
@return First possible Cell on passed Cell's row.
hbase-common/src/main/java/org/apache/hadoop/hbase/PrivateCellUtil.java