code: def get_sieve_capabilities(self):
          
          if isinstance(self.__capabilities["SIEVE"], six.string_types):
              self.__capabilities["SIEVE"] = self.__capabilities["SIEVE"].split()
          return self.__capabilities["SIEVE"]
docs: Returns the SIEVE extensions supported by the server.
  
          They're read from server capabilities. (see the CAPABILITY
          command)
  
          :rtype: string