### Question:
GuavaEvidenceModuleGraph implements ModuleGraph<EvidenceModuleDependency> { @Override public void addModule(HWModule vertex) { graph.addModule(vertex); } GuavaEvidenceModuleGraph(ModuleGraph<TrackingModuleDependency> graph, Optional<Integer> evidenceLimit); @Override Optional<EvidenceModuleDependency> findDependency(HWModule vertex1, HWModule vertex2); @Override void addDependency(EvidenceModuleDependency dependency); @Override void addModule(HWModule vertex); @Override Collection<HWModule> modules(); @Override Collection<HWModule> dependencies(HWModule vertex);  }### Answer:
@Test void addModuleShouldAddVertexToJungGraph() { testee.addModule(m1); assertThat(graph.nodes().contains(m1)).isTrue(); }
@Test void addModuleShouldFailIfVertexAlreadyAdded() { testee.addModule(m1); testee.addModule(m1); assertThat(graph.nodes().size()).isEqualTo(1); }