### Question:
HashMatching { public Map<BlankNode, BlankNode> getMatchings() { return matchings; } HashMatching(Graph tc1, Graph tc2); Map<Set<BlankNode>, Set<BlankNode>> getMatchingGroups(); Map<BlankNode, BlankNode> getMatchings();  }### Answer:
@Test public void twoLine() throws GraphNotIsomorphicException { BlankNodeOrIRI start1 = new BlankNode(); Graph tc1 = Utils4Testing.generateLine(4, start1); tc1.addAll(Utils4Testing.generateLine(5, start1)); BlankNodeOrIRI start2 = new BlankNode(); Graph tc2 = Utils4Testing.generateLine(5, start2); tc2.addAll(Utils4Testing.generateLine(4, start2)); Assert.assertEquals(9, tc1.size()); final Map<BlankNode, BlankNode> mapping = new HashMatching(tc1, tc2).getMatchings(); Assert.assertNotNull(mapping); Assert.assertEquals(10, mapping.size()); }