'Delete a Security Group.
:param security_group: Security Group should be deleted
:type  security_group: :class:`OpenStackSecurityGroup`
:rtype: ``bool``'

def ex_delete_security_group(self, security_group):

    resp = self.connection.request(('/os-security-groups/%s' % security_group.id), method='DELETE')
    return (resp.status in (httplib.NO_CONTENT, httplib.ACCEPTED))
