}

    private String registerCustomLanguage() {
        return """
            @Managed interface CustomSourceSet extends LanguageSourceSet {}
            class CustomSourceSetPlugin extends RuleSource {
                @ComponentType
                void registerCustomLanguage(TypeBuilder<CustomSourceSet> builder) {
                }
            }

                String getData() {
                    "foo"
                }
            }

            class LanguageTypeRules extends RuleSource {
                @ComponentType
                void registerCustomLanguage(TypeBuilder<CustomLanguageSourceSet> builder) {
                }
            }

            apply type: LanguageTypeRules
        """
    }

    /**