Merge "Return a copy of the "real" set in AssociationStore" into tm-dev

        broadcastChange(CHANGE_TYPE_REMOVED, association);

    }

    /**

     * @return a "snapshot" of the current state of the existing associations.

     */

    public @NonNull Collection<AssociationInfo> getAssociations() {

        final Collection<AssociationInfo> allAssociations;

        synchronized (mLock) {

            allAssociations = mIdMap.values();

            // IMPORTANT: make and return a COPY of the mIdMap.values(), NOT a "direct" reference.

            // The HashMap.values() returns a collection which is backed by the HashMap, so changes

            // to the HashMap are reflected in this collection.

            // For us this means that if mIdMap is modified while the iteration over mIdMap.values()

            // is in progress it may lead to "undefined results" (according to the HashMap's

            // documentation) or cause ConcurrentModificationExceptions in the iterator (according

            // to the bugreports...).

            return List.copyOf(mIdMap.values());

        }

        return Collections.unmodifiableCollection(allAssociations);

    }

    public @NonNull List<AssociationInfo> getAssociationsForUser(@UserIdInt int userId) {