code: @Override
      public MarkupDocBuilder apply(MarkupDocBuilder markupDocBuilder, OverviewDocument.Parameters params) {
          Swagger swagger = params.swagger;
          Info info = swagger.getInfo();
          buildDocumentTitle(markupDocBuilder, info.getTitle());
          applyOverviewDocumentExtension(new Context(Position.DOCUMENT_BEFORE, markupDocBuilder));
          buildOverviewTitle(markupDocBuilder, labels.getLabel(Labels.OVERVIEW));
          applyOverviewDocumentExtension(new Context(Position.DOCUMENT_BEGIN, markupDocBuilder));
          buildDescriptionParagraph(markupDocBuilder, info.getDescription());
          buildVersionInfoSection(markupDocBuilder, info);
          buildContactInfoSection(markupDocBuilder, info.getContact());
          buildLicenseInfoSection(markupDocBuilder, info);
          buildUriSchemeSection(markupDocBuilder, swagger);
          buildTagsSection(markupDocBuilder, swagger.getTags());
          buildConsumesSection(markupDocBuilder, swagger.getConsumes());
          buildProducesSection(markupDocBuilder, swagger.getProduces());
          buildExternalDocsSection(markupDocBuilder, swagger.getExternalDocs());
          applyOverviewDocumentExtension(new Context(Position.DOCUMENT_END, markupDocBuilder));
          applyOverviewDocumentExtension(new Context(Position.DOCUMENT_AFTER, markupDocBuilder));
          return markupDocBuilder;
      }
docs: Builds the overview MarkupDocument.
  
  @return the overview MarkupDocument