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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 flat(self, obj, mask=0):
        '''Return the aligned flat size.
        '''
        s = self.base
        if self.leng and self.item > 0:  # include items
            s += self.leng(obj) * self.item
        if _getsizeof:  # _getsizeof prevails
            s = _getsizeof(obj, s)
        if mask:  # align
            s = (s + mask) & ~mask
        return s