code: private void executeOperation(DbUnitDatabasePopulator populator, DataSource dataSource) throws Exception {
  
          Connection connection = null;
  
          try {
              connection = getConnection(dataSource);
              populator.populate(connection);
  
          } finally {
              if (connection != null && !isConnectionTransactional(connection, dataSource)) {
                  // if the connection is transactional, closing it. Otherwise,
                  // expects that the framework will do it
                  releaseConnection(connection, dataSource);
              }
          }
      }
docs: Execute a DBUbit operation