if (plugin.getVersion() == null) {
                PluginVersionRequest request = new DefaultPluginVersionRequest(
                        plugin, session.getRepositorySession(), project.getRemotePluginRepositories());
                plugin.setVersion(pluginVersionResolver.resolve(request).getVersion());
            }
            versions.put(plugin.getKey(), plugin.getVersion());
        }

            return null;
        }

        String version = getVersion(candidateModel);
        if (version != null && parent.getVersion() != null && !version.equals(parent.getVersion())) {
            try {
                VersionRange parentRange = versionParser.parseVersionRange(parent.getVersion());
                if (!parentRange.contains(versionParser.parseVersion(version))) {

    }

    @Nonnull
    @Override
    public String getArtifactId() {
        return project.getArtifactId();
    }

    @Nonnull
    @Override
    public String getVersion() {
        return project.getVersion();
    }

    @Nonnull
    @Override
    public List<Artifact> getArtifacts() {
        org.eclipse.aether.artifact.Artifact pomArtifact = RepositoryUtils.toArtifact(new ProjectArtifact(project));

        pluginArtifactId = plugin.getArtifactId();
        pluginVersion = plugin.getVersion();
    }

    public PluginManagerException(Plugin plugin, String message, Throwable cause) {
        super(message, cause);

        pluginGroupId = plugin.getGroupId();
        pluginArtifactId = plugin.getArtifactId();
        pluginVersion = plugin.getVersion();
    }

        final Parent parent = new Parent();
        parent.setGroupId("org.apache");
        parent.setArtifactId("apache");
        parent.setVersion("1");

        assertNotNull(this.newModelResolver().resolveModel(parent.getDelegate(), new AtomicReference<>()));
        assertEquals("1", parent.getVersion());
    }

    @Test
    void testResolveParentSuccessfullyResolvesExistingParentUsingHighestVersion() throws Exception {

        assertEquals(createSet(artifacts), res.getArtifacts(), "Check artifact list");
        assertEquals("1.0", getArtifact("d", res.getArtifacts()).getVersion(), "Check version");
        assertEquals("2.0", getArtifact("b", res.getArtifacts()).getVersion(), "Check version");
    }

    @Test
    void testResolveNearestNewestIsNearest() throws ArtifactResolutionException, InvalidVersionSpecificationException {

                res.getIncidentEdges(v2).get(0).getVersion(),
                "wrong edge v1-v2 in the resulting graph after resolver");

        assertEquals(
                1, res.getIncidentEdges(v3).size(), "wrong # of edges v1-v3 in the resulting graph after resolver");
        assertEquals(
                "1.1",
                res.getIncidentEdges(v3).get(0).getVersion(),

                && Objects.equals(this.getArtifactId(), that.getArtifactId())
                && Objects.equals(this.getVersion(), that.getVersion())
                && Objects.equals(this.getClassifier(), that.getClassifier());
    }

    @Override
    public int hashCode() {
        return Objects.hash(getGroupId(), getArtifactId(), getVersion(), getClassifier());
    }

    @Override
    public String toString() {

                && Objects.equals(this.getArtifactId(), that.getArtifactId())
                && Objects.equals(this.getVersion(), that.getVersion())
                && Objects.equals(this.getClassifier(), that.getClassifier());
    }

    @Override
    public int hashCode() {
        return Objects.hash(getGroupId(), getArtifactId(), getVersion(), getClassifier());
    }

    @Override
    public String toString() {

                                parent.getVersion()),
                        parent.getGroupId(),
                        parent.getArtifactId(),
                        parent.getVersion());
            }

            String newVersion = versionRangeResult.getHighestVersion().toString();
            if (!parent.getVersion().equals(newVersion)) {