@Nullable
    @Override
    public WorkingCopyFormat execute(boolean lastAttempt) {
      Connection connection = null;
      int userVersion = 0;

      try {
        Class.forName("org.sqlite.JDBC");
        connection = DriverManager.getConnection("jdbc:sqlite:" + FileUtil.toSystemIndependentName(myDbFile.getPath()));
        ResultSet resultSet = connection.createStatement().executeQuery(USER_VERSION_QUERY);

        if (resultSet.next()) {
          userVersion = resultSet.getInt(1);
        }
        else {
          LOG.info("No result while getting user version for " + myDbFile.getPath());
        }
      }
      catch (ClassNotFoundException | SQLException e) {
        LOG.info(e);
      }
      finally {
        close(connection);
      }

      WorkingCopyFormat format = WorkingCopyFormat.getInstance(userVersion);

      return !WorkingCopyFormat.UNKNOWN.equals(format) ? format : null;
    }
@Nullable
    @Override
    public WorkingCopyFormat execute(boolean lastAttempt)