javadocs.getJavadocCss().convention(extension.getSourceRoot().file("css/javadoc.css"));

            // TODO: destinationDirectory should be part of Javadoc
            javadocs.getRenderedDocumentation().from(javadocAll.flatMap(task -> (DirectoryProperty) task.getExtensions().getExtraProperties().get("destinationDirectory")));
        });

        CheckstyleExtension checkstyle = project.getExtensions().getByType(CheckstyleExtension.class);