MockHttpServletRequest request = new MockHttpServletRequest();
MockHttpServletResponse response = new MockHttpServletResponse();
MockFilterChain filterChain = new MockFilterChain();
filter.doFilter(request, response, filterChain);
verify(writer1).writeHeaders(request, response);
verify(writer2).writeHeaders(request, response);
assertThat(filterChain.getRequest()).isEqualTo(request); // verify the filterChain continued
}