@Nullable
                @Override
                public Endpoint selectNow(ClientRequestContext ctx) {
                    if (counter.getAndIncrement() >= failAfter) {
                        throw cause;
                    }
                    return null;
                }
Makes sure an exception thrown by {@link EndpointSelector#selectNow(ClientRequestContext)} are handled
properly at different points of execution.
core/src/test/java/com/linecorp/armeria/client/ClientRequestContextDelayedInitTest.java