def validate(self):
        if 'direction' in self.resource:
            direction = self.resource['direction']
            if direction not in ['ingress', 'egress']:
                raise ValueError(
                    "The direction attribute must be "
                    "either ingress or egress")

        if 'ethertype' is self.resource:
            ethertype = self.resource['ethertype']
            if ethertype not in ['IPv4', 'IPv6']:
                raise ValueError(
                    "The ethertype attribute must be "
                    "either IPv4 or IPv6")

        if 'protocol' in self.resource:
            protocol = self.resource['protocol']
            if protocol not in ['tcp', 'udp', 'icmp']:
                raise ValueError(
                    "The protocol attribute must be "
                    "either tcp, udp or icmp")

        if 'remote_mode' in self.resource:
            remote_mode = self.resource['remote_mode']
            if remote_mode not in ['remote_ip_prefix', 'remote_group_id']:
                raise ValueError(
                    "The remote_mode attribute must be "
                    "either remote_ip_prefix or remote_group_id")

        return True
dataset/ETHPy150Open cloudtools/troposphere/troposphere/openstack/neutron.py/SecurityGroupRule.validate/operator `in` -> `is`