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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 withdrawal_requests(self, timedelta = 86400):
 """ Returns list of withdrawal requests. Each request is represented as a dictionary. By default, the last 24 hours (86400 seconds) are returned. """

        data = {'timedelta': timedelta}
        return self._post("withdrawal_requests/", return_json=True, version=1, data=data)