private static int getSeqNumber(@NotNull PsiClass aClass) {
   // sequence number of this class among its parent' child classes named the same
   PsiElement parent = aClass.getParent();
   if (parent == null) return -1;
   int seqNo = 0;
   for (PsiElement child : parent.getChildren()) {
     if (child == aClass) return seqNo;
     if (child instanceof PsiClass
         && Comparing.strEqual(aClass.getName(), ((PsiClass) child).getName())) {
       seqNo++;
     }
   }
   return -1;
 }
 public final void setSubId(@Nullable String subId) {
   if (Comparing.strEqual(mySubId, subId)) return;
   saveExpandedPaths();
   mySubId = subId;
 }
 public String getPackage() {
   final Data data = getPersistentData();
   return !Comparing.strEqual(data.TEST_OBJECT, TEST_PACKAGE) ? null : data.getPackageName();
 }