this.classifier = classifier;
        this.buildDependencies = taskDependencyFactory.visitingDependencies(context -> context.add(getGenerator()));
    }

    @Override
    public File getFile() {
        return getGenerator().getOutputs().getFiles().getSingleFile();
    }

    private Task getGenerator() {
        return generator.get();
    }

    @Override
    protected String getDefaultExtension() {

    @Override
    public void visitFailure(Throwable failure) {
        failures.add(failure);
    }

    public Set<File> getFiles() {
        return files;
    }

    public Collection<Throwable> getFailures() {
        return failures;
    }

        super(taskDependencyFactory, patternSetFactory);
    }

    @Override
    public Set<File> getFiles() {
        final Set<File> files = new LinkedHashSet<File>();
        visit(new EmptyFileVisitor() {
            @Override
            public void visitFile(FileVisitDetails fileDetails) {
                files.add(fileDetails.getFile());
            }
        });
        return files;
    }

    @Override

        return null;
    }

    @Override
    protected TaskDependency getDefaultBuildDependencies() {
        return buildDependencies;
    }

    @Override
    public File getFile() {
        return generator.get().getOutputs().getFiles().getSingleFile();
    }

    public boolean isEnabled() {
        TaskInternal task = (TaskInternal) generator.get();
        return task.getOnlyIf().isSatisfiedBy(task);
    }

        variant.artifactsProvider(() ->  {
            FileCollection classesDirs = sourceSet.getOutput().getClassesDirs();
            return classesDirs.getFiles().stream()
                .map(file -> new LazyJavaDirectoryArtifact(project.getTaskDependencyFactory(), ArtifactTypeDefinition.JVM_CLASS_DIRECTORY, classesDirs, providerFactory.provider(() -> file)))

        then:
        0 * taskProvider._

        when:
        artifact.file

        then:
        1 * taskProvider.get() >> task
        1 * task.getOutputs() >> outputs
        1 * outputs.getFiles() >> fileCollection
        1 * fileCollection.getSingleFile() >> Stub(File)
        0 * _
    }

    def "fails resolving lazy IvyArtifact for Provider<Task> notation when task has a multiple output files"() {

        then:
        0 * taskProvider._

        when:
        artifact.file

        then:
        1 * taskProvider.get() >> task
        1 * task.getOutputs() >> outputs
        1 * outputs.getFiles() >> fileCollection
        1 * fileCollection.getSingleFile() >> Stub(File)
        0 * _
    }

    def "fails resolving lazy MavenArtifact for Provider<Task> notation when task has a multiple output files"() {

            @Override
            public List<SourceFile> getBeforeFiles() {
                return element.getFiles();
            }

            @Override
            public List<SourceFile> getAfterFiles() {
                return element.getFiles();
            }
        };
    }

    /**

        for (SourceFile sourceFile : getFiles()) {
            sourceFile.writeToDir(srcDir);
        }
    }

    /**
     * Writes the source files of this element to the given source directory.
     */
    public void writeToSourceDir(TestFile sourceDir) {
        for (SourceFile sourceFile : getFiles()) {
            sourceFile.writeToFile(sourceDir.file(sourceFile.getName()));
        }

        """)
    }

    @Override
    String getExpectedOutput() {
        return greeter.expectedOutput + sum.sum(5, 7)
    }

    @Override
    List<SourceFile> getFiles() {
        return super.getFiles() + sum.getFiles()
    }