def getCredentialsCheckers():
        """
        Return credentials checkers for this domain.

        @rtype: L{list} of L{ICredentialsChecker
            <twisted.cred.checkers.ICredentialsChecker>} provider
        @return: Credentials checkers for this domain.
        """

        Return credentials checkers for this domain.

        @rtype: L{list} of L{ICredentialsChecker
            <twisted.cred.checkers.ICredentialsChecker>} provider
        @return: Credentials checkers for this domain.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/mail/interfaces.py