code: @Override
      public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain)
              throws IOException, ServletException {
          filterChain.doFilter(servletRequest, new HttpServletResponseWrapper((HttpServletResponse) servletResponse) {
              @Override
              public void setHeader(String name, String value) {
                  if (!HTTPCacheHeader.ETAG.getName().equalsIgnoreCase(name)) {
                      super.setHeader(name, value);
                  }
              }
          });
      }
docs: <p>
  Disables {@code ETag} HTTP header.
  </p>
  {@inheritDoc}