code: public void close(boolean arbitrarily) {
          if (checkSession()) {
              return;
          }
  
          arbitrarilyClosed = arbitrarily;
          sqlSession.close();
  
          if (log.isDebugEnabled()) {
              log.debug(String.format("Closed %s@%x",
                      sqlSession.getClass().getSimpleName(),
                      sqlSession.hashCode()));
          }
  
          sqlSession = null;
      }
docs: Closes the session arbitrarily.
  If the transaction advice does not finally close the session, the session
  will automatically reopen whenever necessary.
  
  @param arbitrarily true if the session is closed arbitrarily; otherwise false