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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 examples(self):
 """Return examples from all sub-spaces."""

        for examples in product(*[spc.examples for spc in self.spaces]):
            name = ', '.join(name for name, _ in examples)
            element = self.element([elem for _, elem in examples])
            yield (name, element)