}

        @Override
        public boolean equals( Object obj )
        {
            if ( obj == this )
            {
                return true;
            }
            else if ( !( obj instanceof Key ) )
            {
                return false;
            }
            Key that = (Key) obj;
            return artifact.getArtifactId().equals( that.artifact.getArtifactId() )
                && artifact.getGroupId().equals( that.artifact.getGroupId() )
                && artifact.getExtension().equals( that.artifact.getExtension() )
                && artifact.getClassifier().equals( that.artifact.getClassifier() );
        }

        @Override
        public int hashCode()
        {

    implements DependencyGraphTransformer
{

    public DependencyNode transformGraph( DependencyNode node, DependencyGraphTransformationContext context )
        throws RepositoryException
    {
        List<?> sortedConflictIds = (List<?>) context.get( TransformationContextKeys.SORTED_CONFLICT_IDS );
        if ( sortedConflictIds == null )
        {
            ConflictIdSorter sorter = new ConflictIdSorter();
            sorter.transformGraph( node, context );

            sortedConflictIds = (List<?>) context.get( TransformationContextKeys.SORTED_CONFLICT_IDS );
        }

        Map<?, ?> conflictIds = (Map<?, ?>) context.get( TransformationContextKeys.CONFLICT_IDS );
        if ( conflictIds == null )
        {
            throw new RepositoryException( "conflict groups have not been identified" );
        }

        return new SubArtifact( mainArtifact, classifier, extension, file, properties );
    }

    public String getProperty( String key, String defaultValue )
    {
        String value = properties.get( key );
        return ( value != null ) ? value : defaultValue;
    }

    public Map<String, String> getProperties()
    {
        return Collections.unmodifiableMap( properties );
    }

    public Artifact setProperties( Map<String, String> properties )
    {
        if ( this.properties.equals( properties ) || ( properties == null && this.properties.isEmpty() ) )
        {
            return this;
        }
        return new SubArtifact( mainArtifact, classifier, extension, properties, file );