/**
   * Checks that gets work for implicit txs.
   *
   * @param cache Cache to test.
   * @throws Exception If failed.
   */
  private void checkExplicitTx(Ignite ignite, IgniteCache<String, String> cache) throws Exception {
    IgniteCache<String, String> asyncCache = cache.withAsync();

    Transaction tx = ignite.transactions().txStart();

    try {
      assertNull(cache.get("key1"));

      tx.commit();
    } finally {
      tx.close();
    }

    tx = ignite.transactions().txStart();

    try {
      asyncCache.get("key2");

      assertNull(asyncCache.future().get());

      tx.commit();
    } finally {
      tx.close();
    }

    tx = ignite.transactions().txStart();

    try {
      assertTrue(cache.getAll(F.asSet("key3", "key4")).isEmpty());

      tx.commit();
    } finally {
      tx.close();
    }

    tx = ignite.transactions().txStart();

    try {
      asyncCache.getAll(F.asSet("key5", "key6"));

      assertTrue(((Map) asyncCache.future().get()).isEmpty());

      tx.commit();
    } finally {
      tx.close();
    }

    tx = ignite.transactions().txStart();

    try {
      cache.put("key7", "key7");

      cache.remove("key7");

      assertNull(cache.get("key7"));

      tx.commit();
    } finally {
      tx.close();
    }

    checkEmpty(cache);
  }
  /**
   * Adds owned versions to map.
   *
   * @param vers Map of owned versions.
   */
  public void ownedVersions(Map<IgniteTxKey, GridCacheVersion> vers) {
    if (F.isEmpty(vers)) return;

    if (owned == null) owned = new GridLeanMap<>(vers.size());

    owned.putAll(vers);
  }
  /**
   * Checks that gets work for implicit txs.
   *
   * @param cache Cache to test.
   * @throws Exception If failed.
   */
  private void checkImplicitTx(IgniteCache<String, String> cache) throws Exception {
    assertNull(cache.get("key1"));

    IgniteCache<String, String> asyncCache = cache.withAsync();

    asyncCache.get("key2");

    assertNull(asyncCache.future().get());

    assertTrue(cache.getAll(F.asSet("key3", "key4")).isEmpty());

    asyncCache.getAll(F.asSet("key5", "key6"));

    assertTrue(((Map) asyncCache.future().get()).isEmpty());

    cache.put("key7", "key7");
    cache.remove("key7", "key7");
    assertNull(cache.get("key7"));

    checkEmpty(cache);
  }