code: public Swagger2MarkupConfigBuilder withDefinitionOrdering(Comparator<String> definitionOrdering) {
          Validate.notNull(definitionOrdering, "%s must not be null", "definitionOrdering");
          config.definitionOrderBy = OrderBy.CUSTOM;
          config.definitionOrdering = definitionOrdering;
          return this;
      }
docs: Specifies a custom comparator function to order definitions.
  
  @param definitionOrdering definition ordering
  @return this builder