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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 purge(self, symbol):
 """ Delete all metadata of `symbol` Parameters symbol : `str` symbol name to delete """

        logger.warning("Deleting entire metadata history for %r from %r" % (symbol, self._arctic_lib.get_name()))
        self.delete_many({'symbol': symbol})