public static Predicate<String> getImageContainsPredicate(final Collection<Image> images) {
        final Set<String> urls = images == null ? Collections.emptySet() :
            images.stream().map(img -> img == null ? "" : imageUrlForSpoilerCompare(img.getUrl())).collect(Collectors.toSet());
        return url -> urls.contains(imageUrlForSpoilerCompare(url));
    }
Decode a base64-encoded string and save the result into a stream.

@param inString the encoded string
@param out      the stream to save the decoded result into
main/src/main/java/cgeo/geocaching/utils/ImageUtils.java