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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 get_iex_listed_symbol_dir(start=None, **kwargs):

 """
 MOVED to iexfinance.refdata.get_listed_symbol_dir
 """

    import warnings
    warnings.warn(WNG_MSG % ("get_iex_listed_symbol_dir",
                             "refdata.get_iex_listed_symbol_dir"))
    return ListedSymbolDir(start=start, **kwargs)