const int FillCount = 10 * 1000;
    const int ChangeEvery = 100;
    const int UniqCount = 1000;
    
    public static void TestStorageIndex()
    {
      PerfHelper.Measure("MultiDictionary", () =>
      {
        MultiDictionary<int, int> storage = new MultiDictionary<int, int>(false);
        for (int i = 0; i < FillCount * 500; i++)
        {
          storage.Add(i % UniqCount, i);
          if (i % 1001 == 0)
          {
            int a = storage[i % UniqCount].Count;
          }
        }
      });

      PerfHelper.Measure("SortedSet", () =>
      {
        StorageIndex<int> storage = new StorageIndex<int>(null);
        for (int i = 0; i < FillCount * 500; i++)
        {
          storage.AddIndex(i % UniqCount, i);
          if (i % 1001 == 0)
          {
            storage.IndexesOf(i % UniqCount);
          }
        }
      });
    }

-------
MultiDictionary:
  Elapsed: 62.8747s,  MemDelta:   33,13 MB,  GC count: 15
-------
SortedSet:
  Elapsed: 04.4208s,  MemDelta:  115,72 MB,  GC count: 32
-------
HashSet:
  Elapsed: 01.8388s,  MemDelta:  135,84 MB,  GC count: 59
-------
List:
  Elapsed: 02.3754s,  MemDelta:   36,82 MB,  GC count: 41

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