private String id(String aPrefix, TOP aFS) {
int id;
// if we already have an ID for the given FS return it
if (ids.containsKey(aFS.getAddress())) {
id = ids.get(aFS.getAddress());
}
// otherwise generate a new ID
else {
id = counters.getInt(aPrefix);
ids.put(aFS.getAddress(), id);
counters.put(aPrefix, id + 1);
}
return aPrefix + '-' + id;
}
