'Creates OperationContract for deleteLoadBalancer.
To verify the operation, we just check that the AWS resources
created by upsert_load_balancer are no longer visible on AWS.
Args:
use_vpc: [bool] if True delete the VPC load balancer, otherwise
the non-VPC load balancer.'

def delete_load_balancer(self, use_vpc):

    load_balancer_name = self.lb_name
    if (not use_vpc):
        load_balancer_name += '-pub'
    payload = self.agent.make_json_payload_from_kwargs(job=[{'type': 'deleteLoadBalancer', 'cloudProvider': 'aws', 'credentials': self.bindings['SPINNAKER_AWS_ACCOUNT'], 'regions': [self.bindings['TEST_AWS_REGION']], 'loadBalancerName': load_balancer_name}], description='Delete    Load    Balancer:    {0}    in    {1}:{2}'.format(load_balancer_name, self.bindings['SPINNAKER_AWS_ACCOUNT'], self.bindings['TEST_AWS_REGION']), application=self.TEST_APP)
    builder = aws.AwsPythonContractBuilder(self.aws_observer)
    builder.new_clause_builder('Load    Balancer    Removed').call_method(self.elb_client.describe_load_balancers, LoadBalancerNames=[load_balancer_name]).EXPECT(ov_factory.error_list_contains(jp.ExceptionMatchesPredicate((BotoCoreError, ClientError), 'LoadBalancerNotFound')))
    title_decorator = ('_with_vpc' if use_vpc else '_without_vpc')
    return st.OperationContract(self.new_post_operation(title=('delete_load_balancer' + title_decorator), data=payload, path='tasks'), contract=builder.build())
