int nowInSec = (int)(System.currentTimeMillis() / 1000) + 42; //live for 42 seconds
// Add rowA
cfamily.addColumn(new QueryPath("Standard1", null, ByteBufferUtil.bytes("colA")), ByteBufferUtil.bytes("valA"), 1);
cfamily.addColumn(null, new ExpiringColumn(ByteBufferUtil.bytes("colExp"), ByteBufferUtil.bytes("valExp"), 1, 42, nowInSec));
writer.append(Util.dk("rowA"), cfamily);
cfamily.clear();
// Add rowB
cfamily.addColumn(new QueryPath("Standard1", null, ByteBufferUtil.bytes("colB")), ByteBufferUtil.bytes("valB"), 1);
writer.append(Util.dk("rowB"), cfamily);
cfamily.clear();