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")

    }

    @Override
    public boolean getHasInputs() {
        throw failWithUnsupportedMethod("getHasInputs()");
    }

    @Override
    public FileCollection getFiles() {
        throw failWithUnsupportedMethod("getFiles()");
    }

    @Override
    public TaskInputFilePropertyBuilder files(Object... paths) {
        throw failWithUnsupportedMethod("files(Object...)");
    }

    @Override

         *
         * Note that {@link #getFiles()} may contain some files even if this method returns false. This means that the include was partially resolved.
         */
        boolean isComplete();

        Collection<IncludeFile> getFiles();
    }

    interface IncludeFile {
        boolean isQuotedInclude();
        String getPath();

                @Override
                public String getDisplayName() {
                    return DefaultPublicationArtifactSet.this.name;
                }

                @Override
                public Set<File> getFiles() {
                    Set<File> result = new LinkedHashSet<File>();
                    for (PublicationArtifact artifact : DefaultPublicationArtifactSet.this) {
                        result.add(artifact.getFile());

        task.getExecutionData().from(executionData.getFiles());
        task.getClassDirectories().from(classDirectories.getFiles());
        task.getSourceDirectories().from(sourceDirectories.getFiles());
    }

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

    private DefaultTaskProperties(
        ImmutableSortedSet<InputPropertySpec> inputProperties,

        task.includes(fileCollectionFactory.create(new MinimalFileSet() {
            @Override
            public Set<File> getFiles() {
                PlatformToolProvider platformToolProvider = ((NativeToolChainInternal) binary.getToolChain()).select((NativePlatformInternal) binary.getTargetPlatform());

        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 Compiler<ScalaJavaJointCompileSpec> newCompiler(ScalaJavaJointCompileSpec spec) {
        Set<File> scalaClasspathFiles = scalaClasspath.getFiles();
        Set<File> zincClasspathFiles = zincClasspath.getFiles();

        HashedClasspath hashedScalaClasspath = new HashedClasspath(DefaultClassPath.of(scalaClasspathFiles), classpathHasher);