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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def cancel(**kwargs):
 """Cancels work items based on their criteria. Args: **kwargs: Same parameters as the query() method. Returns: The number of tasks that were canceled. """

    task_list = _query(**kwargs)
    for task in task_list:
        task.status = WorkQueue.CANCELED
        task.finished = datetime.datetime.utcnow()
        db.session.add(task)
    return len(task_list)