code: public void sessionCreated(IoSession session) throws Exception {
          SingleSessionIoHandler handler = factory.getHandler(session);
          session.setAttribute(HANDLER, handler);
          handler.sessionCreated();
      }
docs: Creates a new instance with the factory passed to the constructor of
  this class.  The created handler is stored as a session
  attribute named {@link #HANDLER}.
  
  @see org.apache.mina.core.service.IoHandler#sessionCreated(org.apache.mina.core.session.IoSession)