final Extension ext = project.getExtensions().create("conventions", Extension.class);
                    project.getTasks().withType(SomeTask.class).configureEach(task -> {
                        task.getConventionMapping().map("inputProperty", ext::getInputProperty);
                    });
                    project.getTasks().register("ok", SomeTask.class, task -> {
                    });
                }

        conventionMapOutputDirectory(options, htmlReport);
    }

    private static void conventionMapOutputDirectory(TestNGOptions options, final DirectoryReport html) {
        new DslObject(options).getConventionMapping().map("outputDirectory", new Callable<File>() {
            @Override
            public File call() {
                return html.getOutputLocation().getAsFile().getOrNull();
            }
        });
    }