@SuppressWarnings("unchecked")
    public <T> ContentStorageActivityHelper addSelectActionCallback(final SelectAction action, final Class<T> clazz, final Consumer<T> callback) {
        if (!action.callbackParameterClass.isAssignableFrom(clazz)) {
            throw new IllegalArgumentException("Callback for action '" + action + "' must be of type " + action.callbackParameterClass + ", found " + clazz);
        }
        this.selectActionCallbacks.put(action, (Consumer<Object>) callback);
        return this;
    }
Important: this class will only work if you incorporate {@link #onActivityResult(int, int, Intent)}
into the {@link Activity#onActivityResult(int, int, Intent)} method of the using application!
TODO: once Activity ResultAPI is available -> refactor! Watch #9349
main/src/main/java/cgeo/geocaching/storage/ContentStorageActivityHelper.java