'The IMAP4 modified UTF-7 implementation encodes all printable
characters which are in ASCII using the corresponding ASCII byte.'

def test_printableSingletons(self):

    for o in chain(range(32, 38), range(39, 127)):
        charbyte = chr(o).encode()
        self.assertEqual(charbyte, chr(o).encode('imap4-utf-7'))
        self.assertEqual(chr(o), charbyte.decode('imap4-utf-7'))
    self.assertEqual(u'&'.encode('imap4-utf-7'), '&-')
    self.assertEqual('&-'.decode('imap4-utf-7'), u'&')
