docs: public Filter createFilter(FilterConfig filterConfig) {
          LOGGER.entering(SecurityRealm.class.getName(), "createFilter");
          
          Binding binding = new Binding();
          SecurityComponents sc = getSecurityComponents();
          binding.setVariable("securityComponents", sc);
          binding.setVariable("securityRealm",this);
          BeanBuilder builder = new BeanBuilder();
          builder.parse(filterConfig.getServletContext().getResourceAsStream("/WEB-INF/security/SecurityFilters.groovy"),binding);
          WebApplicationContext context = builder.createApplicationContext();
          return (Filter) context.getBean("filter");
      }