* After the buildplan is ready, the build()-method returns the immutable context useful during distribution.
 * This is an inner class, as it must be able to call readRawModel()
 *
 * @since 4.0.0
 */
class DefaultTransformerContextBuilder implements TransformerContextBuilder {
    private final Graph dag = new Graph();
    private final DefaultModelBuilder defaultModelBuilder;
    private final DefaultTransformerContext context;

        if (modelSource instanceof FileModelSource) {
            if (request.getTransformerContextBuilder() instanceof DefaultTransformerContextBuilder) {
                DefaultTransformerContextBuilder contextBuilder =
                        (DefaultTransformerContextBuilder) request.getTransformerContextBuilder();
                contextBuilder.putSource(getGroupId(model), model.getArtifactId(), (FileModelSource) modelSource);