Tree left

                    @Optional @Nested
                    Tree right

                    String nonAnnotated
                }

                @TaskAction void execute() {}
            }
        """

        expect:
        assertValidationFailsWith([

        buildFile << """
            @CacheableTask
            class CustomTask extends DefaultTask {
                @OutputFiles Iterable<File> out

                @TaskAction
                void execute() {
                    out.eachWithIndex { file, index ->
                        file.text = "data\${index + 1}"
                    }
                }
            }

                @Input
                String message = "Hello World"
                @OutputFile
                File outputFile = new File(temporaryDir, "output.txt")

                @TaskAction
                void generate() {
                    outputFile.text = message
                }
            }

            @DisableCachingByDefault

                abstract DirectoryProperty getSources()

                @OutputFile
                abstract RegularFileProperty getOutputFile()

                @TaskAction
                void doSomething() {
                    outputFile.get().asFile.text = "executed"
                }
            }

            tasks.register("taskWithInputs", TaskWithInputs) {

            import ${PropertyWalker.name}
            import ${FileCollectionFactory.name}

            class CustomTask extends DefaultTask {
                @Optional @$annotation.simpleName input
                @TaskAction void doSomething() {
                    def fileCollectionFactory = services.get(FileCollectionFactory)
                    GetInputFilesVisitor visitor = new GetInputFilesVisitor("ownerName", fileCollectionFactory)

        given:
        buildFile << """
            abstract class Foo extends DefaultTask {

                @Inject
                public abstract ${serviceType.name} getInjected()

                @TaskAction
                void action() {
                    println(getInjected())
                }
            }

            tasks.register('foo', Foo)
        """

        when:

                }

                @Input
                public FileTree getFileTree() {
                    return getProject().files().getAsFileTree();
                }

                @TaskAction
                public void doStuff() { }
            }
        """

        when:
        executer.withArgument("-Dorg.gradle.internal.max.validation.errors=7")

        then:

        given:
        server.start()
        buildFile << """
            @ParallelizableTask
            class ParTask extends DefaultTask {
                @TaskAction zzz() { ${server.callFromBuildUsingExpression('name')} }
            }

            task para1(type:ParTask)
            task para2(type:ParTask)
            task parallelTasks(dependsOn:[para1,para2])
        """

                @OutputDirectory abstract DirectoryProperty getOutputClasses()

                Producer() { outputs.upToDateWhen { false } } // TODO doesn't matter, remove this

                @TaskAction void doStuff() {
                    File f = outputClasses.get().asFile
                    f.mkdirs()
                    new File(f, "some.txt") << "some text"
                }
            }

                @OutputFile
                File outputFile

                public TaskWithInputs() {
                    sources = project.files()
                }

                @TaskAction
                void doSomething() {
                    outputFile.withWriter { writer ->
                        sources.each { writer.println it }
                    }
                }
            }