private Set<String> getUsedScopeNames() {
    Set<String> usedScopeNames = new HashSet<>();
    for (int i =0 ; i < myModel.size(); i ++) {
      FileSetDescriptor descriptor = myModel.get(i);
      if (descriptor instanceof NamedScopeDescriptor) {
        usedScopeNames.add(descriptor.getName());
      }
    }
    return usedScopeNames;
  }
private Set<String> getUsedScopeNames()