@Test
  public void testChunkCache() throws IOException {
    Database database = new Database();

    // Round 1: Add chunk to new database version, then add database version
    DatabaseVersion databaseVersion1 = TestDatabaseUtil.createDatabaseVersion();

    ChunkEntry chunkA1 = new ChunkEntry(new byte[] {1, 2, 3, 4, 5, 7, 8, 9, 0}, 12);
    databaseVersion1.addChunk(chunkA1);

    database.addDatabaseVersion(databaseVersion1);
    assertEquals(chunkA1, database.getChunk(new byte[] {1, 2, 3, 4, 5, 7, 8, 9, 0}));

    // Round 2: Add chunk to new database version, then add database version
    DatabaseVersion databaseVersion2 = TestDatabaseUtil.createDatabaseVersion(databaseVersion1);

    ChunkEntry chunkA2 = new ChunkEntry(new byte[] {9, 8, 7, 6, 5, 4, 3, 2, 1}, 112);
    databaseVersion2.addChunk(chunkA2);

    database.addDatabaseVersion(databaseVersion2);
    assertEquals(chunkA1, database.getChunk(new byte[] {1, 2, 3, 4, 5, 7, 8, 9, 0}));
    assertEquals(chunkA2, database.getChunk(new byte[] {9, 8, 7, 6, 5, 4, 3, 2, 1}));

    // Round 3: Add chunk to new database version, then add database version
    DatabaseVersion databaseVersion3 = TestDatabaseUtil.createDatabaseVersion(databaseVersion2);

    ChunkEntry chunkA3 = new ChunkEntry(new byte[] {1, 1, 1, 1, 1, 1, 1, 1, 1}, 192);
    databaseVersion3.addChunk(chunkA3);

    database.addDatabaseVersion(databaseVersion3);
    assertEquals(chunkA1, database.getChunk(new byte[] {1, 2, 3, 4, 5, 7, 8, 9, 0}));
    assertEquals(chunkA2, database.getChunk(new byte[] {9, 8, 7, 6, 5, 4, 3, 2, 1}));
    assertEquals(chunkA3, database.getChunk(new byte[] {1, 1, 1, 1, 1, 1, 1, 1, 1}));
  }
  @Test
  public void testMultiChunkCache() throws IOException {
    Database database = new Database();

    // Round 1: Add chunk to multichunk
    DatabaseVersion databaseVersion1 = TestDatabaseUtil.createDatabaseVersion();

    MultiChunkEntry multiChunkP1 = new MultiChunkEntry(new byte[] {8, 8, 8, 8, 8, 8, 8, 8});
    ChunkEntry chunkA1 = new ChunkEntry(new byte[] {1, 2, 3, 4, 5, 7, 8, 9, 0}, 12);

    multiChunkP1.addChunk(new ChunkEntryId(chunkA1.getChecksum()));
    databaseVersion1.addChunk(chunkA1);
    databaseVersion1.addMultiChunk(multiChunkP1);

    database.addDatabaseVersion(databaseVersion1);

    assertEquals(chunkA1, database.getChunk(new byte[] {1, 2, 3, 4, 5, 7, 8, 9, 0}));
    assertEquals(multiChunkP1, database.getMultiChunk(new byte[] {8, 8, 8, 8, 8, 8, 8, 8}));

    // Round 2: Add chunk to multichunk
    DatabaseVersion databaseVersion2 = TestDatabaseUtil.createDatabaseVersion(databaseVersion1);

    MultiChunkEntry multiChunkP2 = new MultiChunkEntry(new byte[] {7, 7, 7, 7, 7, 7, 7, 7, 7});
    MultiChunkEntry multiChunkP3 = new MultiChunkEntry(new byte[] {5, 5, 5, 5, 5, 5, 5, 5, 5});

    ChunkEntry chunkA2 = new ChunkEntry(new byte[] {9, 2, 3, 4, 5, 7, 8, 9, 0}, 912);
    ChunkEntry chunkA3 = new ChunkEntry(new byte[] {8, 2, 3, 4, 5, 7, 8, 9, 0}, 812);
    ChunkEntry chunkA4 = new ChunkEntry(new byte[] {7, 2, 3, 4, 5, 7, 8, 9, 0}, 712);

    multiChunkP2.addChunk(new ChunkEntryId(chunkA2.getChecksum()));
    multiChunkP2.addChunk(new ChunkEntryId(chunkA3.getChecksum()));
    multiChunkP3.addChunk(new ChunkEntryId(chunkA4.getChecksum()));

    databaseVersion2.addChunk(chunkA2);
    databaseVersion2.addChunk(chunkA3);
    databaseVersion2.addChunk(chunkA4);

    databaseVersion2.addMultiChunk(multiChunkP2);
    databaseVersion2.addMultiChunk(multiChunkP3);

    database.addDatabaseVersion(databaseVersion2);

    // fail("xx");

    assertEquals(chunkA1, database.getChunk(new byte[] {1, 2, 3, 4, 5, 7, 8, 9, 0}));
    assertEquals(chunkA2, database.getChunk(new byte[] {9, 2, 3, 4, 5, 7, 8, 9, 0}));
    assertEquals(chunkA3, database.getChunk(new byte[] {8, 2, 3, 4, 5, 7, 8, 9, 0}));
    assertEquals(chunkA4, database.getChunk(new byte[] {7, 2, 3, 4, 5, 7, 8, 9, 0}));
    assertEquals(multiChunkP1, database.getMultiChunk(new byte[] {8, 8, 8, 8, 8, 8, 8, 8}));
    assertEquals(multiChunkP2, database.getMultiChunk(new byte[] {7, 7, 7, 7, 7, 7, 7, 7, 7}));
    assertEquals(multiChunkP3, database.getMultiChunk(new byte[] {5, 5, 5, 5, 5, 5, 5, 5, 5}));
  }