This endpoint updates the priority of a batch.
priority should follow the same parameters as an individual task's priority, namely that
priority should be between 10 for the lowest and 30 for the highest priority.
Setting a task's
priority will impact the order in which the task is first picked up, but does not guarantee the order in which a task or set of tasks will be returned to you. As a result, tasks that are not yet started can be reprioritized, but tasks that are already started will not be impacted