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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 _delete_rows(args):
 """Delete the given row keys from the given Bigtable. The args are (BigtableSpec, row_keys), but are passed as a single argument in order to work with multiprocessing.Pool.map. This is also the reason why this is a top-level function instead of a method. """

    btspec, row_keys = args
    bt_table = bigtable.Client(btspec.project).instance(
        btspec.instance).table(btspec.table)
    rows = [bt_table.row(k) for k in row_keys]
    for r in rows:
        r.delete()
    bt_table.mutate_rows(rows)
    return row_keys