def render_thumbnail_tag(document, image_options = {}, url_options = {})
      link_to image_tag(thumbnail_url(document)), url_for_document(document)
    end
def render_thumbnail_tag(document, image_options = {}, url_options = {})
      link_to image_tag(thumbnail_url(document)), url_for_document(document)
    end
Override method in Blacklight::CatalogHelperBehavior.