code: public void free()
      {
          BaseMessageManager messageManager = null;
          if (this.getTask() != null) // May have been freed already.
              if (this.getTask().getApplication() != null)
                  messageManager = (BaseMessageManager)((Application)this.getTask().getApplication()).getMessageManager(false);
          if (messageManager != null)
              messageManager.freeFiltersWithListener(this);
          if (m_messageStack != null)
              m_messageStack.free();
          m_messageStack = null;
          super.free();
      }
docs: Free this session.