}
                }

                if (!missing.isEmpty()) {
                    throw e;
                }
            }

            resolved.addAll(result.getArtifacts());
        }

        return resolved;
    }

    private Set<String> getIgnorableArtifacts(Collection<? extends MavenProject> projects) {

    public void addArtifact(Artifact artifact) {
        if (artifacts == null) {
            artifacts = new LinkedHashSet<>();
        }

        artifacts.add(artifact);
    }

    public Set<Artifact> getArtifacts() {
        return artifacts;
    }

    public void addRequestedArtifact(Artifact artifact) {
        if (requestedArtifacts == null) {
            requestedArtifacts = new LinkedHashSet<>();
        }

    /**
     * Returns project's all artifacts as an immutable ordered collection. The collection contains:
     * <ul>
     *   <li>The project's artifacts ({@link Project#getArtifacts()}):
     *     <ul>
     *       <li>The POM artifact (always present)</li>
     *       <li>The main project artifact (if applicable based on packaging)</li>
     *     </ul>
     *   </li>

            node.getArtifact().setScope(artifact.getScope());
        }

        if (Artifact.SCOPE_SYSTEM.equals(node.getArtifact().getScope())
                && (node.getArtifact().getFile() == null)
                && (artifact.getFile() != null)) {
            fireEvent(ResolutionListener.MANAGE_ARTIFACT_SYSTEM_PATH, listeners, node, artifact);
            node.getArtifact().setFile(artifact.getFile());
        }

        /* getArtifact */
        assertFalse(
                wagon.getTransferEventSupport().hasTransferListener(transferListener),
                "Transfer listener is registered before test");
        wagonManager.getArtifact(artifact, repo, transferListener, false);
        assertFalse(

        if (request.isResolveRoot()) {
            try {
                resolve(request.getArtifact(), request);
                result.addArtifact(request.getArtifact());
            } catch (IOException e) {
                result.addMissingArtifact(request.getArtifact());
            }
        }

        if (request.isResolveTransitively()) {

        }

        return null;
    }

    @Override
    public void getArtifact(Artifact artifact, ArtifactRepository repository)
            throws TransferFailedException, ResourceDoesNotExistException {
        getArtifact(artifact, repository, null, false);
    }

    @Override
    public void getArtifact(Artifact artifact, List<ArtifactRepository> remoteRepositories)

        RepositoryMetadata metadata = new ArtifactRepositoryMetadata(request.getArtifact());

        try {
            repositoryMetadataManager.resolve(metadata, request);
        } catch (RepositoryMetadataResolutionException e) {
            throw new ArtifactMetadataRetrievalException(e.getMessage(), e, request.getArtifact());
        }

     */

    @Override
    public ResolutionNode resolveConflict(ResolutionNode node1, ResolutionNode node2) {
        try {
            ArtifactVersion version1 = node1.getArtifact().getSelectedVersion();
            ArtifactVersion version2 = node2.getArtifact().getSelectedVersion();

            return version1.compareTo(version2) <= 0 ? node1 : node2;
        } catch (OverConstrainedVersionException exception) {

     */
    AuthenticationInfo getAuthenticationInfo(String id);

    ProxyInfo getProxy(String protocol);

    void getArtifact(Artifact artifact, ArtifactRepository repository)
            throws TransferFailedException, ResourceDoesNotExistException;

    void getArtifact(Artifact artifact, List<ArtifactRepository> remoteRepositories)
            throws TransferFailedException, ResourceDoesNotExistException;