def links(links = {})
      links.each_pair do |rel, uri|
        link rel, uri if uri
      end
    end
def links(links = {})
      links.each_pair do |rel, uri|
        link rel, uri if uri
      end
    end
Lets you add a series of links for the current resource.
 @param [Hash{Symbol => String}] links a hash of links. Those with nil as the value are skipped.