public void initialize(long value) {
        try {
            counter.initialize(value);
        } catch (Exception e) {
            throw new IllegalStateException("Error initializing atomic counter", e);
        }
    }
Atomically add and return resulting value.

@param delta value to add, may be negative
@return the resulting value
@throws IllegalStateException if addition fails
zkfacade/src/main/java/com/yahoo/vespa/curator/recipes/CuratorCounter.java