@Override
public long[] allSimilarItemIDs(long itemID) {
FastIDSet allSimilarItemIDs = new FastIDSet();
LongPrimitiveIterator allItemIDs = trackData.keySetIterator();
while (allItemIDs.hasNext()) {
long possiblySimilarItemID = allItemIDs.nextLong();
if (!Double.isNaN(itemSimilarity(itemID, possiblySimilarItemID))) {
allSimilarItemIDs.add(possiblySimilarItemID);
}
}
return allSimilarItemIDs.toArray();