'This action is only used by the Amazon EC2 Container Service
agent, and it is not intended for use outside of the agent.
Returns an endpoint for the Amazon EC2 Container Service agent
to poll for updates.
:type container_instance: string
:param container_instance: The container instance UUID or full Amazon
Resource Name (ARN) of the container instance. The ARN contains the
`arn:aws:ecs` namespace, followed by the region of the container
instance, the AWS account ID of the container instance owner, the
`container-instance` namespace, and then the container instance
UUID. For example, arn:aws:ecs: region : aws_account_id :container-
instance/ container_instance_UUID .'

def discover_poll_endpoint(self, container_instance=None):

    params = {}
    if (container_instance is not None):
        params['containerInstance'] = container_instance
    return self._make_request(action='DiscoverPollEndpoint', verb='POST', path='/', params=params)
