private void deleteAllVersionsBefore(Table ht, byte[] cf, int rowIdx, int colIdx, long version)
    throws IOException {
    byte row[] = Bytes.toBytes("row:" + rowIdx);
    byte column[] = Bytes.toBytes("column:" + colIdx);
    Delete del = new Delete(row);
    del.addColumns(cf, column, version);
    ht.delete(del);
  }
For row/column specified by rowIdx/colIdx, delete all cells preceeding the specified version.
hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestMultipleTimestamps.java