@property<EOL><INDENT>def auth(self):<DEDENT>
if self._auth is None:<EOL><INDENT>self._auth = AuthTypesList(<EOL>self._version,<EOL>account_sid=self._solution['<STR_LIT>'],<EOL>domain_sid=self._solution['<STR_LIT>'],<EOL>)<EOL><DEDENT>return self._auth<EOL>
Access the auth

:returns: twilio.rest.api.v2010.account.sip.domain.auth_types.AuthTypesList
:rtype: twilio.rest.api.v2010.account.sip.domain.auth_types.AuthTypesList