@Override
    public ReleasableHolder<EventLoop> acquireEventLoop(SessionProtocol sessionProtocol,
                                                        EndpointGroup endpointGroup,
                                                        @Nullable Endpoint endpoint) {
        return httpClientFactory.acquireEventLoop(sessionProtocol, endpointGroup, endpoint);
    }
A {@link ClientFactory} which combines all discovered {@link ClientFactory} implementations.

<h2>How are the {@link ClientFactory}s discovered?</h2>

<p>{@link DefaultClientFactory} looks up the {@link ClientFactoryProvider}s available in the current JVM
using Java SPI (Service Provider Interface). The {@link ClientFactoryProvider} implementations will create
the {@link ClientFactory} implementations.
core/src/main/java/com/linecorp/armeria/client/DefaultClientFactory.java