### Question:
NetworkSnapshot { public static NetworkSnapshot create(Set<? extends Vertex> vertices) { return new NetworkSnapshot(vertices); } private  NetworkSnapshot(Collection<? extends Vertex> vertices); static NetworkSnapshot create(Set<? extends Vertex> vertices); void apply();  }### Answer:
@Test public void itInspectsTheVerticesState() { Vertex v1 = mock(Vertex.class); Vertex v2 = mock(Vertex.class); NetworkSnapshot.create(ImmutableSet.of(v1, v2)); verify(v1).getState(); verify(v2).getState(); verifyNoMoreInteractions(v1, v2); }