@VisibleForTesting
    AbstractEventLoopEntry[] entries(SessionProtocol sessionProtocol,
                                     EndpointGroup endpointGroup,
                                     @Nullable Endpoint endpoint) {
        return state(sessionProtocol, endpointGroup, endpoint).entries();
    }
Returns the index of {@link #eventLoops} which an {@link AbstractEventLoopState} will use to acquire an
event loop from. This also sets the index for the next {@link AbstractEventLoopState} which calls this
method.
core/src/main/java/com/linecorp/armeria/client/DefaultEventLoopScheduler.java