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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 pages(self):
 """ The aggregate pages of all the parser objects. """

        pages = []
        for har_dict in self.har_data:
            har_parser = HarParser(har_data=har_dict)
            if self.page_id:
                for page in har_parser.pages:
                    if page.page_id == self.page_id:
                        pages.append(page)
            else:
                pages = pages + har_parser.pages
        return pages