code: public HttpSession getSession(boolean create)
      {        
          if (_session != null && ((SessionManager.Session)_session).isValid())
              return _session;
          
          _session=null;
          
          String id = getRequestedSessionId();
          
          if (id != null)
          {
              _session=_servletHandler.getHttpSession(id);
              if (_session == null && !create)
                  return null;
          }
          
          if (_session == null && create)
          {
              _session=newSession();
          }
          
          return _session;
      }
docs: /* ------------------------------------------------------------