code: @Override
      public void onLogoutSuccess(final HttpServletRequest httpServletRequest,
              final HttpServletResponse response,
              final Authentication authentication)
              throws IOException, ServletException {
          final Map<String, String> result = new HashMap<>();
          result.put("result", "success");
          response.setContentType("application/json");
          response.getWriter().write(objectMapper.writeValueAsString(result));
          response.setStatus(HttpServletResponse.SC_OK);
      }
docs: {@inheritDoc}