ResolutionNode a2n = createResolutionNode(a2);

        assertResolveConflict(a1n, a1n, a2n);
    }

    /**
     * Tests that <code>a:1.0</code> wins in the scenario:
     * <pre>
     * a:2.0
     * a:1.0
     * </pre>
     */
    @Test
    void testEqualReversed() {
        ResolutionNode a2n = createResolutionNode(a2);
        ResolutionNode a1n = createResolutionNode(a1);

        Artifact a2 = repositorySystem.createArtifact("testGroup", "testArtifact", "1.2.3", "jar");
        @SuppressWarnings("deprecation")
        ArtifactRepository lr2 = new DelegatingLocalArtifactRepository(repositorySystem.createDefaultLocalRepository());
        ArtifactRepository rr2 = repositorySystem.createDefaultRemoteRepository();
        a2.setDependencyFilter(new ExcludesArtifactFilter(Arrays.asList("foo")));

        ResolutionNode a2n = createResolutionNode(a2);

        assertResolveConflict(a2n, a1n, a2n);
    }

    /**
     * Tests that <code>a:2.0</code> wins in the scenario:
     * <pre>
     * a:2.0
     * a:1.0
     * </pre>
     */
    @Test
    void testEqualReversed() {
        ResolutionNode a2n = createResolutionNode(a2);
        ResolutionNode a1n = createResolutionNode(a1);

    assertThat(dispatcher.runningCalls())
      .containsExactlyInAnyOrder(a1, a2)
    assertThat(dispatcher.queuedCalls()).isEmpty()

    // Cancel some calls. That doesn't impact running or queued.
    a2.cancel()
    a3.cancel()
    assertThat(dispatcher.runningCalls())
      .containsExactlyInAnyOrder(a1, a2)
    assertThat(dispatcher.queuedCalls()).isEmpty()

    // Let the calls finish.

        ResolutionNode a2n = createResolutionNode(a2);

        assertResolveConflict(a1n, a1n, a2n);
    }

    /**
     * Tests that <code>a:2.0</code> wins in the scenario:
     * <pre>
     * a:2.0
     * a:1.0
     * </pre>
     */
    @Test
    void testEqualReversed() {
        ResolutionNode a2n = createResolutionNode(a2);
        ResolutionNode a1n = createResolutionNode(a1);

        ResolutionNode a2n = createResolutionNode(a2);

        assertResolveConflict(a1n, a1n, a2n);
    }

    /**
     * Tests that <code>a:2.0</code> wins in the scenario:
     * <pre>
     * a:2.0
     * a:1.0
     * </pre>
     */
    @Test
    void testEqualReversed() {
        ResolutionNode a2n = createResolutionNode(a2);
        ResolutionNode a1n = createResolutionNode(a1);

        Set<Artifact> artifacts = new LinkedHashSet<>(4);
        artifacts.add(new DefaultArtifact("g", "a1", "v", "compile", "jar", "", null));
        artifacts.add(new DefaultArtifact("g", "a2", "v", "compile", "jar", "", null));
        artifacts.add(new DefaultArtifact("g", "a3", "v", "compile", "jar", "", null));
        artifacts.add(new DefaultArtifact("g", "a4", "v", "compile", "jar", "", null));

                return model;
            }
        }
    }

    private boolean withinSameGav(Artifact a1, Artifact a2) {
        return Objects.equals(a1.getGroupId(), a2.getGroupId())
                && Objects.equals(a1.getArtifactId(), a2.getArtifactId())
                && Objects.equals(a1.getVersion(), a2.getVersion());
    }

         assertEquals(5, itemList1.size());

         final SynonymItem synonymItem1 = itemList1.get(0);
         synonymItem1.setNewInputs(new String[] { "a1", "a2" });
         synonymItem1.setNewOutputs(new String[] { "A1", "A2" });
         synonymFile.update(synonymItem1);
         final PagingList<SynonymItem> itemList2 = synonymFile.selectList(0, 20);
         assertEquals(5, itemList2.size());

    //
    // 1. Subscribers to events posted on different threads can be interleaved with each other
    //    freely. (A event on one thread, B event on another could yield any of
    //    [a1, a2, a3, b1, b2], [a1, b2, a2, a3, b2], [a1, b2, b3, a2, a3], etc.)
    // 2. It's possible for subscribers to actually be dispatched to in a different order than they
    //    were added to the queue. It's easily possible for one thread to take the head of the