default FilterCategory category() {
        Filter f = getClass().getAnnotation(Filter.class);
        if (f != null) {
            return f.category();
        } else {
            return FilterCategory.UNSPECIFIED;
        }
    }
Classify a filter by category.

@return FilterCategory the classification of this filter
zuul-core/src/main/java/com/netflix/zuul/filters/ZuulFilter.java