@NotNull
        @Override
        public Collection<TypeMigrationUsageInfo> getNodes() {
          final Set<TypeMigrationUsageInfo> infos = new HashSet<>();
          for (Map.Entry<TypeMigrationUsageInfo, HashSet<Pair<TypeMigrationUsageInfo, PsiType>>> entry : myRootsTree.entrySet()) {
            infos.add(entry.getKey());
            infos.addAll(ContainerUtil.map(entry.getValue(), pair -> pair.getFirst()));
          }
          return infos;
        }
@NotNull
        @Override
        public Collection<TypeMigrationUsageInfo> getNodes()