def builder = TransformExecutionResult.builderFor(inputArtifact, outputDir)
        for (File file in files) {
            builder.addOutput(file) {}
        }
        return builder.build()
    }

    TestFile file(String path) {
        temporaryFolder.file(path)
    }

        GroupedTaskOutputFixture task = tasks.get(taskName);
        if (task == null) {
            task = new GroupedTaskOutputFixture(taskName);
            tasks.put(taskName, task);
        }

        task.addOutput(taskOutput);
        task.setOutcome(taskOutcome);
    }

    private void consumeTransformOutput(Matcher matcher) {
        String initialSubjectType = matcher.group(1);
        String subject = matcher.group(2);

import static org.gradle.util.internal.CollectionUtils.join;

public abstract class GroupedNodeFixture {

    private final List<String> outputs = new ArrayList<>(1);

    public void addOutput(String transformOutput) {
        outputs.add(transformOutput);
    }

    public String getOutput() {
        List<String> nonEmptyOutputs = filter(outputs, string -> !string.equals(""));

 */
public abstract class GroupedWorkOutputFixture {

    private final List<String> outputs = new ArrayList<>(1);

    /**
     * Adds an output entry to the group.
     */
    public void addOutput(String output) {
        outputs.add(output);
    }

    /**
     * Returns concatenated non-empty output entries.
     */
    public String getOutput() {

        return outputFile;
    }

    private File resolveAndRegister(Object path, Consumer<File> prepareOutputLocation) {
        File output = resolver.resolve(path);
        resultBuilder.addOutput(output, prepareOutputLocation);
        return output;
    }

    private static void validateOutputExists(File outputDir, File output) {
        if (!output.exists()) {

        /**
         * Adds an output location to the result.
         *
         * @param workspaceAction an action to run when the output is a produced output in the workspace.
         */
        public void addOutput(File output, Consumer<File> workspaceAction) {
            if (output.equals(inputArtifact)) {
                delegate.addEntireInputArtifact();
            } else if (output.equals(outputDir)) {