code: def scheme_host_port_prefix(self, scheme='http', host='host',
                                  port=None, prefix=None):
          
          uri = scheme + '://' + host
          if (port and not ((scheme == 'http' and port == 80) or
                            (scheme == 'https' and port == 443))):
              uri += ':' + str(port)
          if (prefix):
              uri += '/' + prefix
          return uri
docs: Return URI composed of scheme, server, port, and prefix.