protected final CuratorFramework buildCuratorFramework() {
        if (client != null) {
            return client;
        }
        assert customizers != null;
        assert clientBuilder != null;
        customizers.build().forEach(c -> c.accept(clientBuilder));
        return clientBuilder.build();
    }
Returns a newly-created {@link CuratorFramework} based on the configuration properties added to
this builder if {@link #isUserSpecifiedCuratorFramework()} is true.
Otherwise, the {@link CuratorFramework} specified when creating this builder will be returned.
zookeeper3/src/main/java/com/linecorp/armeria/common/zookeeper/AbstractCuratorFrameworkBuilder.java