when:
        formatter.node("thing ")
        formatter.appendTypes(Class, Number, String)

        then:
        formatter.toString() == toPlatformLineSeparators("thing (Class, Number, String)")
    }

    def "can append empty array of types"() {
        when:
        formatter.node("thing ")
        formatter.appendTypes()

        then:

  const int num_results_before_region =
      AppendTypes(&output_types, parallel_execute, 0, region_index);
  // Append updated results from merged execute.
  output_types.append(merged_execute_launch.getResultTypes().begin(),
                      merged_execute_launch.getResultTypes().end());
  const int num_regions = parallel_execute_op->getNumRegions();
  const int num_results_after_region = AppendTypes(

            appendValue(value);
        }
        append("]");
        return this;
    }

    /**
     * Appends some user provided values to the current node.
     */
    public TreeFormatter appendTypes(Type... types) {
        // Implementation is currently dumb, can be made smarter
        append("(");
        for (int i = 0; i < types.length; i++) {
            Type type = types[i];
            if (type == null) {