filterElem.putString(ATTRIB_NAME, flt.getName());
for (ARestriction<?> rest : flt.getRestrictions()) {
final IMemento clauseElem = filterElem.createChild(ELEM_CLAUSE);
clauseElem.putString(ATTRIB_FIELD, rest.getField().getKey());
clauseElem.putInteger(ATTRIB_OPERATOR, rest.getOperator().getId());
rest.visit(new IRestrictionVisitor() {
/* (non-Javadoc)
* @see net.sf.logsaw.core.query.IRestrictionVisitor#visit(net.sf.logsaw.core.query.LevelRestriction)
*/
@Override
public void visit(LevelRestriction restriction) {