private String extension, directory, classifier, packaging, language;
    private boolean includesDependencies, addedToClasspath;

    public void setExtension(String extension) {
        this.extension = extension;
    }

    @Override
    public String getExtension() {
        return extension;
    }

    public void setDirectory(String directory) {
        this.directory = directory;
    }

    @Override

    }

    public String getType() {
        return type;
    }

    @Override
    public String getExtension() {
        if (extension == null) {
            return type;
        }
        return extension;
    }

    public void setExtension(final String extension) {
        this.extension = extension;
    }

    @Override
    public String getClassifier() {

            SnapshotVersion sv = new SnapshotVersion();
            sv.setClassifier(artifact.getClassifier());
            sv.setExtension(artifact.getExtension());
            sv.setVersion(getVersion());
            sv.setUpdated(lastUpdated);
            versions.put(getKey(sv.getClassifier(), sv.getExtension()), sv);
        }

        Versioning versioning = recessive.getVersioning();
        if (versioning != null) {

            SnapshotVersion sv = new SnapshotVersion();
            sv.setClassifier(artifact.getClassifier());
            sv.setExtension(artifact.getExtension());
            sv.setVersion(version);
            sv.setUpdated(lastUpdated);

            versions.put(getKey(sv.getClassifier(), sv.getExtension()), sv);
        }

        artifacts.clear();

        Versioning versioning = recessive.getVersioning();

            path.append(ARTIFACT_SEPARATOR).append(artifact.getClassifier());
        }

        if (artifactHandler.getExtension() != null
                && !artifactHandler.getExtension().isEmpty()) {
            path.append(GROUP_SEPARATOR).append(artifactHandler.getExtension());
        }

        return path.toString();
    }

    @Override

        List<Artifact> mains = new ArrayList<>();
        for (Artifact artifact : artifacts) {
            if ("pom".equals(artifact.getExtension()) || artifact.getExtension().startsWith("pom.")) {
                if (CONSUMER_POM_CLASSIFIER.equals(artifact.getClassifier())) {
                    consumers.add(artifact);
                } else if ("".equals(artifact.getClassifier())) {
                    mains.add(artifact);
                }

     * The dot separator is not included in the returned string.
     *
     * @return the file extension or an empty string if none, never {@code null}
     * @see ArtifactCoordinates#getExtension()
     */
    @Nonnull
    String getExtension();

    /**
     * Determines whether this artifact uses a snapshot version.
     *
     * @return {@code true} if the artifact is a snapshot, {@code false} otherwise

            path.append(ARTIFACT_SEPARATOR).append(artifact.getClassifier());
        }

        if (artifactHandler.getExtension() != null
                && !artifactHandler.getExtension().isEmpty()) {
            path.append(GROUP_SEPARATOR).append(artifactHandler.getExtension());
        }

        return path.toString();
    }

    @Override

        path.append(artifact.getExtension()).append("s/");

        path.append(artifact.getArtifactId()).append('-').append(artifact.getVersion());

        if (!artifact.getClassifier().isEmpty()) {
            path.append('-').append(artifact.getClassifier());
        }

        path.append('.').append(artifact.getExtension());

        return path.toString();
    }

    @Override

    }

    /**
     * @throws Exception
     */
    public void testGetExtension() throws Exception {
        assertEquals("1", "xml", ResourceUtil.getExtension("aaa/bbb.xml"));
        assertEquals("2", null, ResourceUtil.getExtension("aaa"));
    }

    /**
     * @throws Exception
     */
    public void testRemoteExtension() throws Exception {