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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 doc(self):
 """Returns a PyQuery object of the response's content"""

        if hasattr(self, '_doc'):
            return self._doc
        elements = self.etree
        doc = self._doc = PyQuery(elements)
        doc.make_links_absolute(utils.text(self.url))
        return doc