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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 RecreateInstanceDisks(r, instance, disks=None, nodes=None):
 """Recreate an instance's disks. @type instance: string @param instance: Instance name @type disks: list of int @param disks: List of disk indexes @type nodes: list of string @param nodes: New instance nodes, if relocation is desired @rtype: string @return: job id """


    body = {}

    if disks is not None:
        body["disks"] = disks
    if nodes is not None:
        body["nodes"] = nodes

    return r.request("post", "/2/instances/%s/recreate-disks" % instance,
                     content=body)