@Override
protected float getScore(final List<Character> chars, final long ts) {
// TODO: very short words, very long words.
lastAdd = ts;
final char[] a = DigestedWords.toArray(chars);
final STBKLResult result = tree.lookup(a, range, maxSeek, true);
if (result.isNew) added ++;
// Calculate time score.
float score = 0f;
if (!result.isNew && result.match != null){
final long age = ts - result.match.ts;