'Test _xml_start_tag() with attributes requiring escaping'

def test_xml_start_tag_with_attributes_to_escape(self):

    self.writer._xml_start_tag('foo', [('span', '&<>"')])
    exp = '<foo    span="&amp;&lt;&gt;&quot;">'
    got = self.fh.getvalue()
    self.assertEqual(got, exp)
