@NotNull
  private static Set<String> getKeys(@NotNull PostfixTemplateProvider provider) {
    Set<String> result = new HashSet<>();
    for (PostfixTemplate template : PostfixTemplatesUtils.getAvailableTemplates(provider)) {
      result.add(template.getKey());
    }
    return result;
  }
@NotNull
  private static Set<String> getKeys(@NotNull PostfixTemplateProvider provider)