task.outputOptions(options -> options.setBackends(singletonList("html5")));
            // TODO: This breaks the provider
            task.setOutputDir(extension.getUserManual().getStagingRoot().dir("render-single-html").get().getAsFile());
        });

        TaskProvider<AsciidoctorTask> userguideSinglePagePdf = tasks.register("userguideSinglePagePdf", AsciidoctorTask.class, task -> {

             OutputStreamWriter outputStream = new OutputStreamWriter(new FileOutputStream(destination), outputEncoding)) {
            String html = renderer.render(parser.parseReader(inputStream));
            outputStream.write(html);
        } catch (IOException e) {
            throw new UncheckedIOException(e);
        }
    }

            Element simplelist = document.createElement("simplelist");

            int columns = 3;
            if (classDoc.getSubClasses().size() <= 3) {
                // if there are only 3 or fewer known subtypes, render them
                // in a single column
                columns = 1;
            }
            simplelist.setAttribute("columns", String.valueOf(columns));
            simplelist.setAttribute("type", "vert");