def extract_partial(doc)
    next_links = doc.xpath('//atom:link[@rel="next"]', @ds_namespaces)
    @has_partial = next_links.any?
    if @has_partial
      uri = Addressable::URI.parse(next_links[0]['href'])
      uri.query_values = uri.query_values.merge @additional_params unless @additional_params.empty?
      @next_uri = uri.to_s
    end
  end
def extract_partial(doc)
    next_links = doc.xpath('//atom:link[@rel="next"]', @ds_namespaces)
    @has_partial = next_links.any?
    if @has_partial
      uri = Addressable::URI.parse(next_links[0]['href'])
      uri.query_values = uri.query_values.merge @additional_params unless @additional_params.empty?
      @next_uri = uri.to_s
    end
  end
Tests for and extracts the next href of a partial