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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 _maybe_cache(arg, format, cache, convert_listlike):
 """ Create a cache of unique dates from an array of dates Parameters arg : integer, float, string, datetime, list, tuple, 1-d array, Series format : string Strftime format to parse time cache : boolean True attempts to create a cache of converted values convert_listlike : function Conversion function to apply on dates Returns ------- cache_array : Series Cache of converted, unique dates. Can be empty """

    from pandas import Series
    cache_array = Series()
    if cache:
        # Perform a quicker unique check
        from pandas import Index
        unique_dates = Index(arg).unique()
        if len(unique_dates) < len(arg):
            cache_dates = convert_listlike(unique_dates.to_numpy(),
                                           True, format)
            cache_array = Series(cache_dates, index=unique_dates)
    return cache_array