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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 _expand_rec_to_vars(var_items, rec_items, input_order, items_by_key, parallel):
 """Expand record to apply to number of variants. Alternative approach to _nest_vars_in_rec to combining a single record with multiple variants. """

    num_items = var_items
    var_items = list(var_items)[0]
    if rec_items:
        for rec_key in (k for (k, t) in input_order.items() if t == "record"):
            rec_vals = items_by_key[rec_key]
            if len(rec_vals) == 1 and var_items > 1:
                items_by_key[rec_key] = rec_vals * var_items
            else:
                assert var_items == len(rec_vals), (var_items, rec_vals)
    return items_by_key, num_items