}
  }

  if (!inputs.empty() || !outputs.empty()) {
    arg_nodes->resize(inputs.size());
    ret_nodes->resize(outputs.size());

    for (Node* n : GetOrderedNodes()) {
      // Handle inputs/arguments.
      auto input_it = inputs.find(n->name());
      if (input_it != inputs.end()) {
        (*arg_nodes)[input_it->second] = {n, 0};
      }

                    def input = inputArtifact.get().asFile
                    def output = outputs.file(input.name + ".blue")
                    assert output.parentFile.directory && output.parentFile.list().length == 0
                    println "Transforming \${input.name} to \${output.name}"
                    println "Input exists: \${input.exists()}"