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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 _dict_to_map_str_str(self, d):
 """ Thrift requires the params and headers dict values to only contain str values. """

        return dict(map(
            lambda (k, v): (k, str(v).lower() if isinstance(v, bool) else str(v)),
            d.iteritems()
        ))