def provide_label(self):
        """The name and shape of label provided by this iterator"""
        if self.rename_label is None:
            return sum([i.provide_label for i in self.iters], [])
        else:
            return sum([[
                DataDesc(r[x.name], x.shape, x.dtype)
                if isinstance(x, DataDesc) else DataDesc(*x)
                for x in i.provide_label
            ] for r, i in zip(self.rename_label, self.iters)], [])
The name and shape of label provided by this iterator
lib/utils/PrefetchingIter.py