def test_load(self):
        """
        Verify that the loader returns a tag with the correct children.
        """
        loader = self.loaderFactory()
        tag, = loader.load()

        warnings = self.flushWarnings(offendingFunctions=[self.loaderFactory])
        if self.deprecatedUse:
            self.assertEqual(len(warnings), 1)
            self.assertEqual(warnings[0]['category'], DeprecationWarning)
            self.assertEqual(
                warnings[0]['message'],
                "Passing filenames or file objects to XMLFile is "
                "deprecated since Twisted 12.1.  Pass a FilePath instead.")
        else:
            self.assertEqual(len(warnings), 0)

        self.assertEqual(tag.tagName, 'p')
        self.assertEqual(tag.children, [u'Hello, world.'])

        Verify that the loader returns a tag with the correct children.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/web/test/test_template.py