get (HTTPClient::DigestAuth)

    # File lib/httpclient/auth.rb, line 291
        def get(req)
          target_uri = req.header.request_uri
          param = Util.hash_find_value(@challenge) { |uri, v|
            Util.uri_part_of(target_uri, uri)
          }
          return nil unless param
          user, passwd = Util.hash_find_value(@auth) { |uri, auth_data|
            Util.uri_part_of(target_uri, uri)
          }
          return nil unless user
          uri = req.header.request_uri
          calc_cred(req.header.request_method, uri, user, passwd, param)
        end