docs: def collection(name=None):
      """Render the collection page.
  
      It renders it either with a collection specific template (aka
      collection_{collection_name}.html) or with the default collection
      template (collection.html).
      """
      if name is None:
          collection = Collection.query.get_or_404(1)
      else:
          collection = Collection.query.filter(
              Collection.name == name).first_or_404()
  
      # TODO add breadcrumbs
      # breadcrumbs = current_breadcrumbs + collection.breadcrumbs(ln=g.ln)[1:]
      return render_template([
          'invenio_collections/collection_{0}.html'.format(collection.id),
          'invenio_collections/collection_{0}.html'.format(slugify(name, '_')),
          current_app.config['COLLECTIONS_DEFAULT_TEMPLATE']
      ], collection=collection)