private static void addOldStillExistingTags(
     @NotNull Set<VcsRef> allRefs,
     @NotNull Set<String> currentTags,
     @NotNull Set<VcsRef> previousRefs) {
   for (VcsRef ref : previousRefs) {
     if (!allRefs.contains(ref) && currentTags.contains(ref.getName())) {
       allRefs.add(ref);
     }
   }
 }
 @Override
 public boolean equals(@NotNull VcsRef ref1, @NotNull VcsRef ref2) {
   return ref1.getName().equals(ref2.getName()) && ref1.getType().equals(ref2.getType());
 }
 @Override
 public int computeHashCode(@NotNull VcsRef ref) {
   return 31 * ref.getName().hashCode() + ref.getType().hashCode();
 }
 @Override
 public String fun(VcsRef ref) {
   return ref.getType() == GitRefManager.TAG ? ref.getName() : null;
 }