private static CopyOnWriteContent createInCopyOnWriteState(Map<String,Object> unmodifiableMap) {
        CopyOnWriteContent content=new CopyOnWriteContent();
        content.unmodifiableMap = unmodifiableMap;
        return content;
    }
Create a COPYONWRITE instance with some initial state
container-search/src/main/java/com/yahoo/search/query/profile/CopyOnWriteContent.java