private T init() {
        initializationLock.lock();
        try {
            if (!initialized) {
                value = create.get();
                initialized = true;
                delegate = this::internalGet;
            }
            return delegate.get();
        } finally {
            initializationLock.unlock();
        }
    }
Execute a method on the object returned from the supplier if the object was already created.
Skips execution if the underlying object was never created.

@param consumer A consumer for the object returned by this supplier.
core/src/main/java/org/jdbi/v3/core/internal/MemoizingSupplier.java