import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkState;
import static java.util.Arrays.asList;
+import static java.util.Collections.emptyList;
import java.util.ArrayList;
+import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.UUID;
+import javax.annotation.Nonnull;
import com.google.common.base.Function;
import com.google.common.base.Optional;
public static final Function<Album, List<Album>> FLATTENER = new Function<Album, List<Album>>() {
@Override
+ @Nonnull
public List<Album> apply(Album album) {
+ if (album == null) {
+ return emptyList();
+ }
List<Album> albums = new ArrayList<Album>();
albums.add(album);
for (Album subAlbum : album.getAlbums()) {
public static final Function<Album, List<Image>> IMAGES = new Function<Album, List<Image>>() {
@Override
+ @Nonnull
public List<Image> apply(Album album) {
- return album.getImages();
+ return (album != null) ? album.getImages() : Collections.<Image>emptyList();
}
};