def METHOD_NAME(self, httpRequest, sessionId, configurationAttributes):
    print "Application session. Starting external session"
    user_name = sessionId.getSessionAttributes().get(Constants.AUTHENTICATED_USER)
    first_session = self.isFirstSession(user_name)
    if not first_session:
        facesMessages = CdiUtil.bean(FacesMessages)
        facesMessages.add(FacesMessage.SEVERITY_ERROR, "Please, end active session first!")
        return False
    print "Application session. External session started successfully"
    return True