title: Is txn.commit() required with Xodus?
body: <p>Here's my code:</p>
  
  <p><code>
      @Override
      public void updateUser(String instance, String storeName, final String userId,
                             final String newUsername, final String newPassword) {
          if (storeName == null || storeName == null) {
              return;
          }
          final PersistentEntityStore entityStore = PersistentEntityStores.newInstance(xodusRoot + instance);
          entityStore.executeInTransaction(new StoreTransactionalExecutable() {
              @Override
              public void execute(@NotNull final StoreTransaction txn) {
                  EntityId roleEntityId = txn.toEntityId(userId);
                  final Entity entity = txn.getEntity(roleEntityId);
                  if(newUsername != null) {
                      entity.setProperty("username", newUsername);
                  }
                  if(newPassword != null) {
                      entity.setProperty("password", newPassword);
                  }
                  //txn.commit();
              }
          });
          entityStore.close();
      }
  </code>
  I want to know if for this code, is <code>txn.commit();</code> required so the transaction to be executed, how about for rollback? </p>
  
  <p>ps. </p>
  
  <p>I wanted this code to return boolean if all transaction completed successfully but cannot find way except for <code>txn.commit</code> which returns boolean, is that the way? So it must be required? </p>