@NotNull
 private Set<Usage> getReadOnlyUsages() {
   final Set<Usage> result = new THashSet<Usage>();
   final Set<Map.Entry<Usage, UsageNode>> usages = myUsageNodes.entrySet();
   for (Map.Entry<Usage, UsageNode> entry : usages) {
     Usage usage = entry.getKey();
     UsageNode node = entry.getValue();
     if (node != null && node != NULL_NODE && !node.isExcluded() && usage.isReadOnly()) {
       result.add(usage);
     }
   }
   return result;
 }
  @Override
  @NotNull
  public Set<Usage> getExcludedUsages() {
    Set<Usage> result = new THashSet<Usage>();
    for (Map.Entry<Usage, UsageNode> entry : myUsageNodes.entrySet()) {
      UsageNode node = entry.getValue();
      Usage usage = entry.getKey();
      if (node == NULL_NODE || node == null) {
        continue;
      }
      if (node.isExcluded()) {
        result.add(usage);
      }
    }

    return result;
  }