@Override
        public final Set<File> getFiles() {
            if (hasOutputs()) {
                return getOutputs();
            }
            return Collections.emptySet();
        }

        @Override
        public final TaskDependency getBuildDependencies() {
            if (hasOutputs()) {
                return AbstractNativeLibraryBinarySpec.this.getBuildDependencies();
            }

        @Override
        public String getDisplayName() {
            return "Link files for " + DefaultSharedLibraryBinarySpec.this.getDisplayName();
        }

        @Override
        protected boolean hasOutputs() {
            return hasSources() && !isResourceOnly();
        }

        @Override
        protected Set<File> getOutputs() {
            return Collections.singleton(getSharedLibraryLinkFile());

    private final Set<Node> nodesYetToConsumeOutput = new HashSet<>();
    final Set<String> outputPaths = new HashSet<>();
    final Set<String> destroyablePaths = new HashSet<>();
    boolean hasFileInputs;
    boolean hasOutputs;
    boolean hasLocalState;
    boolean hasValidationProblem;
    private boolean outputProduced;

    void started() {
        outputProduced = true;
    }

    boolean isOutputProducedButNotYetConsumed() {

        outputFilePropertySpecs.forEach(spec -> {
            File outputLocation = spec.getOutputFile();
            mutations.outputPaths.add(outputLocation.getAbsolutePath());
            mutations.hasOutputs = true;
        });
    }

    private void addLocalStateFilesToMutations(FileCollection localStateFiles) {
        final MutationInfo mutations = getMutationInfo();
        localStateFiles.forEach(file -> {

        @Override
        public String getDisplayName() {
            return "Link files for " + DefaultStaticLibraryBinarySpec.this.getDisplayName();
        }

        @Override
        protected boolean hasOutputs() {
            return hasSources() || !additionalLinkFiles.isEmpty();
        }

        @Override
        protected Set<File> getOutputs() {
            Set<File> allFiles = new LinkedHashSet<File>();

    }

    @Override
    public boolean hasOutput(final long classId, final TestOutputEvent.Destination destination) {
        final boolean[] hasOutput = new boolean[1];
        withReader(new Action<TestOutputStore.Reader>() {
            @Override
            public void execute(TestOutputStore.Reader reader) {
                hasOutput[0] = reader.hasOutput(classId, destination);
            }
        });

    }

    @Override
    public boolean hasOutput(final long classId, final TestOutputEvent.Destination destination) {
        final boolean[] hasOutput = new boolean[1];
        withReader(new Action<TestOutputStore.Reader>() {
            @Override
            public void execute(TestOutputStore.Reader reader) {
                hasOutput[0] = reader.hasOutput(classId, destination);
            }
        });

        when:
        provider.hasOutput(1, TestOutputEvent.Destination.StdOut)
        provider.writeAllOutput(1, TestOutputEvent.Destination.StdOut, writer)
        provider.writeTestOutput(1, 11, TestOutputEvent.Destination.StdOut, writer)
        provider.writeNonTestOutput(1, TestOutputEvent.Destination.StdOut, writer)

        then:
        1 * provider1.hasOutput(12, TestOutputEvent.Destination.StdOut)

            }
        }
    }

    @Override
    public boolean hasOutput(long classId, final TestOutputEvent.Destination destination) {
        for (DelegateProvider delegateProvider : classOutputProviders.get(classId)) {
            if (delegateProvider.provider.hasOutput(delegateProvider.id, destination)) {
                return true;
            }
        }
        return false;

        then:
        outputs.hasOutput
    }

    void hasOutputsWhenNonEmptyOutputFilesRegistered() {
        when:
        outputs.file('a')

        then:
        outputs.hasOutput
    }

    void hasOutputsWhenUpToDatePredicateRegistered() {
        when:
        outputs.upToDateWhen { false }

        then:
        outputs.hasOutput
    }