@Test
public void missingEdge() {

    final TestAUGBuilder builder = buildAUG().withActionNodes(":a1:", ":a2:").withEdge(":a1:", ORDER, ":a2:");
    Overlap overlap = buildOverlap(builder).withNode(":a1:").withNode(":a2:").build();
    MissingElementViolationPredicate strategy = new MissingElementViolationPredicate();
    assertTrue(strategy.apply(overlap).orElse(false));
}