def render_extensions(key, options = {})
      extensions = find_extension_partials(key, options.delete(:folder)).map do |partial|
        render options.merge(:partial => partial)
      end
      safe_join(extensions)
    end
def render_extensions(key, options = {})
      extensions = find_extension_partials(key, options.delete(:folder)).map do |partial|
        render options.merge(:partial => partial)
      end
      safe_join(extensions)
    end
Renders all partials with names that match "_[ key ]_*.[ format ].[ handler ]"
 in alphabetical order.
 Accepts an additional option :folder to pass an additional folder to search
 extension partials in.