protected int calculateConcurency() {
        final int customLimit = filterConcurrencyCustom.get();
        return customLimit != DEFAULT_FILTER_CONCURRENCY_LIMIT ? customLimit : filterConcurrencyDefault.get();
    }
@Test
    void validateFilterSpecificConcurrencyLimitOverride() {
        config.setProperty("zuul.filter.concurrency.limit.default", 7000);
        config.setProperty("zuul.ConcInboundFilter.in.concurrency.limit", 4300);
        final int[] limit = {0};

        class ConcInboundFilter extends BaseFilter {

            @Override
            public Observable applyAsync(ZuulMessage input) {
                limit[0] = calculateConcurency();
                return Observable.just("Done");
            }

            @Override
            public FilterType filterType() {
                return FilterType.INBOUND;
            }

            @Override
            public boolean shouldFilter(ZuulMessage msg) {
                return true;
            }
        }
        new ConcInboundFilter().applyAsync(new ZuulMessageImpl(new SessionContext(), new Headers()));
        Truth.assertThat(limit[0]).isEqualTo(4300);
    }