OperationIdentifier parentId = progressEventConsumer.findStartedParentId(buildOperation);
                InternalOperationDescriptor descriptor = mapper.createDescriptor(buildOperation.getDetails(), buildOperation, parentId);
                return new EnabledOperation(descriptor, mapper, progressEventConsumer);
            } else {
                return null;
            }

            TaskNode taskNode = (TaskNode) node;
            return descriptors.get(taskNode.getTask().getTaskIdentity());
        }
        return null;
    }

    @Override
    public DefaultTaskDescriptor createDescriptor(ExecuteTaskBuildOperationDetails details, BuildOperationDescriptor buildOperation, @Nullable OperationIdentifier parent) {
        OperationIdentifier id = buildOperation.getId();

    }

    @Override
    public ConfiguredModuleComponentRepository createResolver() {
        return createRealResolver();
    }

    @Override
    protected IvyRepositoryDescriptor createDescriptor() {
        Set<String> schemes = getSchemes();
        validate(schemes);

        URI url = urlArtifactRepository.getUrl();

            super(instantiator, authenticationContainer, TestUtil.objectFactory(), null, new VersionParser())
        }

        @Override
        protected RepositoryDescriptor createDescriptor() {
            throw new UnsupportedOperationException()
        }

        @Override
        ConfiguredModuleComponentRepository createResolver() {
            throw new UnsupportedOperationException()

        when:
        generator.started(operation, startEvent)

        then:
        1 * consumer.findStartedParentId(operation) >> parentId
        1 * mapper2.createDescriptor(details, operation, parentId) >> clientDescriptor
        1 * mapper2.createStartedEvent(clientDescriptor, details, startEvent) >> clientStartEvent
        1 * consumer.started(clientStartEvent)
        0 * _

    }

    @Override
    public ConfiguredModuleComponentRepository createResolver() {
        return createRealResolver();
    }

    @Override
    protected FlatDirRepositoryDescriptor createDescriptor() {
        IvyRepositoryDescriptor.Builder builder = new IvyRepositoryDescriptor.Builder(getName(), null);
        builder.setM2Compatible(false);
        builder.setLayoutType("Unknown");

    }

    @Override
    public List<? extends BuildOperationTracker> getTrackers() {
        return ImmutableList.of(taskTracker);
    }

    @Override
    public DefaultTestDescriptor createDescriptor(ExecuteTestBuildOperationType.Details details, BuildOperationDescriptor buildOperation, @Nullable OperationIdentifier parent) {
        TestDescriptor testDescriptor = details.getTestDescriptor();

        for (Class<?> inputType : action.getInputTypes()) {
            MetadataDescriptorFactory descriptorFactory = new MetadataDescriptorFactory(metadata);
            Object descriptor = descriptorFactory.createDescriptor(inputType);
            if (descriptor != null) {
                inputs.add(descriptor);
            }
        }
        return inputs;
    }

    public void setArtifactUrls(Iterable<?> urls) {
        invalidateDescriptor();
        additionalUrls = Lists.newArrayList(urls);
    }

    @Override
    protected MavenRepositoryDescriptor createDescriptor() {
        URI rootUri = validateUrl();
        return new MavenRepositoryDescriptor.Builder(getName(), rootUri)
            .setAuthenticated(usesCredentials())