/// <summary>
 /// Register Handlebars helpers.
 /// </summary>
 public void RegisterHelpers()
 {
     foreach (var helper in Helpers)
     {
         HandlebarsLib.RegisterHelper(helper.Key,
                                      (output, context, args) => helper.Value(output, context, args));
     }
 }
 /// <summary>
 /// Register Handlebars helpers.
 /// </summary>
 /// <param name="helperName">Helper name.</param>
 /// <param name="helper">Helper delegate.</param>
 public virtual void RegisterHelper(string helperName, Action <TextWriter, object, object[]> helper)
 {
     HandlebarsLib.RegisterHelper(helperName, (output, context, args) => helper(output, context, args));
 }