code: private void commit(boolean force) {
  		if (_db == null) {
  			return;
  		}
  		
  		if (_transaction && !force) {
  			return;
  		}
  		
  		try {
  			_db.commit();
  		} catch (Exception e) {
  			throw new IllegalStateException("Could not commit transaction", e);
  		}
  	}
docs: Commit database transaction. This method is a NOOP if there is no
  database or if {@link #_transaction} is currently true.
  @param force true if the database transaction should be committed
  regardless of the {@link #_transaction} flag.