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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 GetNodeStorageUnits(r, node, storage_type, output_fields):
 """ Gets the storage units for a node. @type node: str @param node: the node whose storage units to return @type storage_type: str @param storage_type: storage type whose units to return @type output_fields: str @param output_fields: storage type fields to return @rtype: int @return: job id where results can be retrieved """


    query = {
        "storage_type": storage_type,
        "output_fields": output_fields,
    }

    return r.request("get", "/2/nodes/%s/storage" % node, query=query)