'Delete a Rule from a Security Group.
:param rule: Rule should be deleted
:type  rule: :class:`OpenStackSecurityGroupRule`
:rtype: ``bool``'

def ex_delete_security_group_rule(self, rule):

    resp = self.connection.request(('/os-security-group-rules/%s' % rule.id), method='DELETE')
    return (resp.status == httplib.NO_CONTENT)
