class DefaultArtifactFilterManager implements ArtifactFilterManager {

    // this is a live injected collection
    protected final List<ArtifactFilterManagerDelegate> delegates;

    protected Set<String> excludedArtifacts;

    private final Set<String> coreArtifacts;

    @Inject
    public DefaultArtifactFilterManager(List<ArtifactFilterManagerDelegate> delegates, CoreExports coreExports) {
        this.delegates = delegates;
        this.coreArtifacts = coreExports.getExportedArtifacts();
    }

    private synchronized Set<String> getExcludedArtifacts() {
        if (excludedArtifacts == null) {
            excludedArtifacts = new LinkedHashSet<>(coreArtifacts);
        }
        return excludedArtifacts;
    }

    /**
     * Returns the artifact filter for the core + extension artifacts.
     *
     * @see org.apache.maven.ArtifactFilterManager#getArtifactFilter()
     */
    public ArtifactFilter getArtifactFilter() {
        Set<String> excludes = new LinkedHashSet<>(getExcludedArtifacts());

        for (ArtifactFilterManagerDelegate delegate : delegates) {
            delegate.addExcludes(excludes);
        }

        return new ExclusionSetFilter(excludes);
    }

    /**
     * Returns the artifact filter for the standard core artifacts.
     *
     * @see org.apache.maven.ArtifactFilterManager#getCoreArtifactFilter()
     */
    public ArtifactFilter getCoreArtifactFilter() {
        return new ExclusionSetFilter(getCoreArtifactExcludes());
    }

    public void excludeArtifact(String artifactId) {
        getExcludedArtifacts().add(artifactId);
    }

    public Set<String> getCoreArtifactExcludes() {<FILL_FUNCTION_BODY>}
}

        Set<String> excludes = new LinkedHashSet<>(coreArtifacts);

        for (ArtifactFilterManagerDelegate delegate : delegates) {
            delegate.addCoreExcludes(excludes);
        }

        return excludes;
    
<no_super_class>