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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 assignment_to_plan(assignment):
 """Convert an assignment to the format used by Kafka to describe a reassignment plan. """

    return {
        'version': 1,
        'partitions':
        [{'topic': t_p[0],
          'partition': t_p[1],
          'replicas': replica
          } for t_p, replica in six.iteritems(assignment)]
    }