GetsOperation.Callback getsCb = null;
if(op.getCallback() instanceof GetOperation.Callback) {
getCb=new MultiGetOperationCallback(
op.getCallback(), op.getKeys().size());
} else {
getsCb=new MultiGetsOperationCallback(
op.getCallback(), op.getKeys().size());
}
for(String k : op.getKeys()) {
rv.add(getCb == null ? gets(k, getsCb) : get(k, getCb));
}