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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def grant_user_to_vswitch(self, vswitch_name, userid):
 """Set vswitch to grant user."""

        smt_userid = zvmutils.get_smt_userid()
        requestData = ' '.join((
            'SMAPI %s API Virtual_Network_Vswitch_Set_Extended' % smt_userid,
            "--operands",
            "-k switch_name=%s" % vswitch_name,
            "-k grant_userid=%s" % userid,
            "-k persist=YES"))

        try:
            self._request(requestData)
        except exception.SDKSMTRequestFailed as err:
            LOG.error("Failed to grant user %s to vswitch %s, error: %s"
                      % (userid, vswitch_name, err.format_message()))
            self._set_vswitch_exception(err, vswitch_name)