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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 _combine_cwl_records(recs, record_name, parallel):
 """Provide a list of nexted CWL records keyed by output key. Handles batches, where we return a list of records, and single items where we return one record. """

    if parallel not in ["multi-batch", "single-split", "multi-combined", "batch-single"]:
        assert len(recs) == 1, pprint.pformat(recs)
        return {record_name: recs[0]}
    else:
        return {record_name: recs}