getExtensions().remove(coreExtension);
    } // -- void removeExtension( CoreExtension )

    /**
     * Set a set of build extensions to use from this project.
     *
     * @param extensions a extensions object.
     */
    public void setExtensions(List<CoreExtension> extensions) {
        this.extensions = extensions;
    } // -- void setExtensions( List )

    /**
     * Set the modelEncoding field.

                "http://maven.apache.org/EXTENSIONS/1.1.0 https://maven.apache.org/xsd/core-extensions-1.1.0.xsd");
        if ((coreExtensions.getExtensions() != null)
                && (coreExtensions.getExtensions().size() > 0)) {
            for (Iterator iter = coreExtensions.getExtensions().iterator(); iter.hasNext(); ) {
                CoreExtension o = (CoreExtension) iter.next();

        for (Artifact artifact : artifacts) {
            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);
        }

            }

            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);
        }

        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() {
        return classifier;
    }

public class ArtifactHandlerMock implements ArtifactHandler {

    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) {