'C{codecs.getwriter(\'imap4-utf-7\')} returns the I{imap4-utf-7} stream
writer class.'

def test_getwriter(self):

    output = BytesIO()
    writer = codecs.getwriter('imap4-utf-7')(output)
    writer.write(u'Hello\xffworld')
    self.assertEqual(output.getvalue(), 'Hello&AP8-world')
