public ClientFactoryBuilder maxNumEventLoopsFunction(ToIntFunction<Endpoint> maxNumEventLoopsFunction) {
        checkState(!options.containsKey(ClientFactoryOptions.EVENT_LOOP_SCHEDULER_FACTORY),
                   "maxNumEventLoopsPerEndpoint() and eventLoopSchedulerFactory() are mutually exclusive.");
        maxNumEventLoopsFunctions.add(requireNonNull(maxNumEventLoopsFunction, "maxNumEventLoopsFunction"));
        return this;
    }
Sets the {@link ToIntFunction} which takes an {@link Endpoint} and produces the maximum number of
{@link EventLoop}s which will be used to handle connections to the specified {@link Endpoint}.
The function should return {@code 0} or a negative value for the {@link Endpoint}s which it
doesn't want to handle. For example: <pre>{@code
ToIntFunction<Endpoint> function = endpoint -> {
    if (endpoint.equals(Endpoint.of("foo.com"))) {
        return 5;
    }
    if (endpoint.host().contains("bar.com")) {
        return Integer.MAX_VALUE; // The value will be clamped at the number of event loops.
    }
    return -1; // Should return 0 or a negative value to use the default value.
}
}</pre>
core/src/main/java/com/linecorp/armeria/client/ClientFactoryBuilder.java