}
                    }
                });
            }

            @Override
            public void visitTransformSources(TransformSourceVisitor visitor) {
                throw new UnsupportedOperationException();
            }

            @Override
            public void visitExternalArtifacts(Action<ResolvableArtifact> visitor) {

    }

    @Override
    public void visitTransformSources(TransformSourceVisitor visitor) {
        // Should not be called
        throw new UnsupportedOperationException();
    }

    @Override
    public void visitExternalArtifacts(Action<ResolvableArtifact> visitor) {

        ImmutableList.Builder<TransformStepNode> builder = ImmutableList.builder();
        sourceArtifacts.visitTransformSources(new ResolvedArtifactSet.TransformSourceVisitor() {
            @Override
            public void visitArtifact(ResolvableArtifact artifact) {
                TransformUpstreamDependencies upstreamDependencies = dependenciesResolver.dependenciesFor(transformStep);

    override fun visit(visitor: ResolvedArtifactSet.Visitor) {
        throw UnsupportedOperationException("Should not be called")
    }

    override fun visitTransformSources(visitor: ResolvedArtifactSet.TransformSourceVisitor) {
        throw UnsupportedOperationException("Should not be called")
    }

    override fun visitExternalArtifacts(visitor: Action<ResolvableArtifact>) {