@Requires("allStates != null")
@Ensures("result != null")
public Set<Integer> getKeys(final List<List<Object>> allStates) {
final HashSet<Integer> keys = new HashSet<Integer>();
root.find(allStates, 0, keys);
return keys;
}
@Requires("states != null")
@Ensures("result >= -1")
public int getKey(final List<Object> states) {
return root.find(states, 0);
}
