@Test
  public void twoTransactions() throws Exception {
    try (final KeyValueStorage store = createStore()) {

      final KeyValueStorageTransaction tx1 = store.startTransaction();
      final KeyValueStorageTransaction tx2 = store.startTransaction();

      tx1.put(bytesOf(1), bytesOf(1));
      tx2.put(bytesOf(2), bytesOf(2));

      tx1.commit();
      tx2.commit();

      assertThat(store.get(bytesOf(1))).contains(bytesOf(1));
      assertThat(store.get(bytesOf(2))).contains(bytesOf(2));
    }
  }
Two transactions.

@throws Exception the exception
testutil/src/main/java/org/hyperledger/besu/kvstore/AbstractKeyValueStorageTest.java