@SuppressWarnings("unchecked")
    public <T> T computeCachedValueIfAbsent(Object key, Supplier<? extends T> supplier) {
        return (T) cache.computeIfAbsent(key, __ -> supplier.get());
    }
Returns the cached value, or computes and caches it if not present.
linguistics/src/main/java/com/yahoo/language/process/InvocationContext.java