@Test
    void testOrdinaryRequest() throws Exception {
        final HttpRequest req = newReq();
        final ClientRequestContext ctx = newContext();
        final HttpResponseWriter actualRes = HttpResponse.streaming();

        when(delegate.execute(ctx, req)).thenReturn(actualRes);

        final ConcurrencyLimitingClient client =
                newDecorator(1).apply(delegate);
        assertThat(client.numActiveRequests()).isZero();

        final HttpResponse res = client.execute(ctx, req);
        assertThat(res.isOpen()).isTrue();
        await().untilAsserted(() -> assertThat(client.numActiveRequests()).isEqualTo(1));

        closeAndDrain(actualRes, res);

        assertThat(res.isOpen()).isFalse();
        await().untilAsserted(() -> assertThat(client.numActiveRequests()).isZero());
    }
Tests the request pattern  that does not exceed maxConcurrency.
core/src/test/java/com/linecorp/armeria/client/limit/ConcurrencyLimitingClientTest.java