MockHttpServletRequest request = new MockHttpServletRequest();
MockHttpServletResponse response = new MockHttpServletResponse();
RequestHeaderAuthenticationFilter filter = new RequestHeaderAuthenticationFilter();
filter.setAuthenticationManager(createAuthenticationManager());
filter.setCheckForPrincipalChanges(true);
request.addHeader("SM_USER", "cat");
filter.doFilter(request, response, new MockFilterChain());
request = new MockHttpServletRequest();
request.addHeader("SM_USER", "dog");
filter.doFilter(request, response, new MockFilterChain());
Authentication dog = SecurityContextHolder.getContext().getAuthentication();