Find a security group by name.

        Returns a :class:`NovaSecGroup` instance if found, otherwise returns
        None.

def find_secgroup(self, name):
        """
        Find a security group by name.

        Returns a :class:`NovaSecGroup` instance if found, otherwise returns
        None.

        """
        groups = self.nova.security_groups.findall(name=name)
        if groups:
            return NovaSecGroup(groups[0])