def test_missingDocumentFactory(self):
        def cb(ignored):
            # The old flattener unconditionally logs errors.
            self.flushLoggedErrors(MissingDocumentFactory)
        d = self.assertFailure(self._render(Element()), FlattenerError)
        d.addCallback(cb)
        return d
Return a new ``<w:p>`` element inserted directly prior to this one.
dataset/ETHPy150Open twisted/nevow/nevow/test/test_element.py/FlattenIntegrationTests.test_missingDocumentFactory--crossover with--dataset/ETHPy150Open python-openxml/python-docx/docx/oxml/text/paragraph.py/CT_P.add_p_before