### Question:
DBSCAN { public Set<Set<T>> cluster(Iterable<? extends T> data) { Validate.notNull(data, "data must not be null"); Set<Set<T>> clusters = new HashSet<>(); Set<T> visited = new HashSet<>(); Set<T> clustered = new HashSet<>(); for (T d : data) { if (visited.contains(d)) { continue; } visited.add(d); Set<T> neighbors = regionQuery(d, data); if (neighbors.size() < minPts) { clusters.add(Collections.singleton(d)); } else { Set<T> currentCluster = expandCluster(d, neighbors, data, visited, clustered); clustered.addAll(currentCluster); clusters.add(currentCluster); } } return clusters; } DBSCAN(double eps, int minPts, Distance<? super T> distance); Set<Set<T>> cluster(Iterable<? extends T> data); @Override String toString();  }### Answer:
@Test public void testDBSCANStrings() { Set<String> strings = new HashSet<>(); strings.add("apple"); strings.add("aple"); strings.add("aapple"); strings.add("apples"); strings.add("banana"); strings.add("pea"); strings.add("peas"); strings.add("peanut"); DBSCAN<String> dbscan = new DBSCAN<String>(0.1, 2, new JaroWinklerSimilarity()); Set<Set<String>> clusters = dbscan.cluster(strings); assertEquals(4, clusters.size()); }