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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 _process_table(self, cache=True):
 """Applies the post processors"""

        table = self.source()
        assert not isinstance(table, None.__class__), \
            "{}.source needs to return something, not None".format(self.__class__.__name__)
        table = post_process(table, self.post_processors())
        if cache:
            self.to_cache(table)
        return table