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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:

async def slice(self, offs, size=None, iden=None):
        '''
        Yield a number of items from the CryoTank starting at a given offset.

        Args:
            offs (int): The index of the desired datum (starts at 0)
            size (int): The max number of items to yield.

        Yields:
            ((index, object)): Index and item values.
        '''
        if iden is not None:
            self.setOffset(iden, offs)

        for i, (indx, item) in enumerate(self._items.iter(offs)):

            if size is not None and i >= size:
                return

            yield indx, item