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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 label_from_func(self, func:Callable, label_cls:Callable=None, **kwargs)->'LabelList':
        "Apply `func` to every input to get its label."
        return self._label_from_list([func(o) for o in self.items], label_cls=label_cls, **kwargs)