public CuratorDiscoverySpecBuilder converter(
            Function<? super ServiceInstance<?>, Endpoint> converter) {
        checkState(instanceId == null, "converter() and instanceId() are mutually exclusive.");
        checkState(useSsl == null, "converter() and useSsl() are mutually exclusive.");
        this.converter = requireNonNull(converter, "converter");
        return this;
    }
Sets the specified converter to convert a {@link ServiceInstance} into an {@link Endpoint}.
If you don't want to connect to the service, you can simply return {@code null} in the converter.
zookeeper3/src/main/java/com/linecorp/armeria/client/zookeeper/CuratorDiscoverySpecBuilder.java