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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 truncate_volume(self, volume, size):
 """Truncate a volume to a new, smaller size. :param volume: Name of the volume to truncate. :type volume: str :param size: Size in bytes, or string representing the size of the volume to be created. :type size: int or str :returns: A dictionary mapping "name" to volume and "size" to the volume's new size in bytes. :rtype: ResponseDict .. warnings also:: Data may be irretrievably lost in this operation. .. note:: A snapshot of the volume in its previous state is taken and immediately destroyed, but it is available for recovery for the 24 hours following the truncation. """

        return self.set_volume(volume, size=size, truncate=True)