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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 num_examples(self):
 """The number of examples this subset spans."""

        if self.is_list:
            return len(self.list_or_slice)
        else:
            start, stop, step = self.slice_to_numerical_args(
                self.list_or_slice, self.original_num_examples)
            return stop - start