@Override
public CRDTMessage add(UnorderedNode<T> father, T element) throws PreconditionException {
if (!wcp.lookup().contains(father))
throw new PreconditionException("Adding node " + element + " with father not in the tree");
if (father.getChild(element) != null)
throw new PreconditionException("Adding node " + element + " already present under father");
CRDTMessage msg = null;
for (List<T> wf : wcp.addMapping(father)) {
List<T> w = new Word(wf, element);
CRDTMessage add = words.add(w);
msg = msg == null ? add : msg.concat(add);
}
return msg;
}
