} else if (expression == "getFiles { true }") {

    @Override
    public Iterator<File> iterator() {
        return getFiles().iterator();
    }

    @Override
    public String getAsPath() {
        showGetAsPathDeprecationWarning();
        return GUtil.asPath(this);
    }

    private void showGetAsPathDeprecationWarning() {
        List<String> filesAsPaths = this.getFiles().stream()
            .map(File::getPath)

            listener.visitArtifacts(new EndCollection(this));
            return;
        }

        FileCollectionInternal fileCollection = dependencyMetadata.getFiles();
        Set<File> files;
        try {
            files = fileCollection.getFiles();
        } catch (Exception throwable) {
            listener.visitArtifacts(new BrokenArtifacts(throwable));
            return;
        }

        when:
        Set<File> files = collection.getFiles()

        then:
        collection.toString() == 'test files'
        files == [tmpDir.file('abc')] as Set
    }

    def 'resolving collection source #description can return null'() {
        def collection = factory.resolving('test files', input)

        when:
        Set<File> files = collection.getFiles()

        then:
        files.isEmpty()

            for (NativeDependencySet nativeDependencySet : binary.getLibs()) {
                runtimeFiles.add(getFiles(nativeDependencySet));
            }
            return runtimeFiles;
        }

        protected abstract FileCollection getFiles(NativeDependencySet nativeDependencySet);
    }

        graph.getResolutionFailure().ifPresent(ex -> {
            throw ex;
        });
        return graph;
    }

    @Override
    public FileCollectionInternal getFiles() {
        return doGetArtifactView(Actions.doNothing()).getFiles();
    }

    @Override
    public ArtifactCollectionInternal getArtifacts() {
        return doGetArtifactView(Actions.doNothing()).getArtifacts();
    }

        when:
        FileCollection sum = collection1.plus(collection2)

        then:
        assertThat(sum, instanceOf(UnionFileCollection.class))
        assertThat(sum.getFiles(), equalTo(toLinkedSet(file1, file2, file3)))
    }

    def "can add collections using + operator"() {
        File file1 = new File("f1")
        File file2 = new File("f2")
        File file3 = new File("f3")

            outputFilesCollector.getFileProperties(),
            serviceReferencesVisitor.getServiceReferences(),
            outputUnpacker.hasDeclaredOutputs(),
            localStateVisitor.getFiles(),
            destroyablesVisitor.getFiles(),
            validationVisitor.getTaskPropertySpecs(),
            validationContext);
    }

    private DefaultTaskProperties(
        ImmutableSortedSet<InputPropertySpec> inputProperties,

        println "files 11: " + configurations.compile.resolvedConfiguration.getFiles { true }.collect { it.name }
        println "files 12: " + configurations.compile.resolvedConfiguration.lenientConfiguration.getFiles { true }.collect { it.name }
    }
}
"""

        when:

        }

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

        @Override
        @Deprecated
        public Set<File> getFiles(Spec<? super Dependency> dependencySpec) {
            DeprecationLogger.deprecateMethod(LenientConfiguration.class, "getFiles(Spec)")