def test_fetchBodyStructureMultipart(self, uid=0):
        """
        L{IMAP4Client.fetchBodyStructure} can also parse the response to a
        I{FETCH BODYSTRUCTURE} command for a multipart message.
        """
        self.function = self.client.fetchBodyStructure
        self.messages = '3:9,10:*'
        innerMessage = FakeyMessage({
                'content-type': 'text/plain; name=thing; key="value"',
                'content-id': 'this-is-the-content-id',
                'content-description': 'describing-the-content-goes-here!',
                'content-transfer-encoding': '8BIT',
                'content-language': 'fr',
                'content-md5': '123456abcdef',
                'content-disposition': 'inline',
                'content-location': 'outer space',
            }, (), b'', b'Body\nText\nGoes\nHere\n', 919293, None)
        self.msgObjs = [FakeyMessage({
                'content-type': 'multipart/mixed; boundary="xyz"',
                'content-language': 'en',
                'content-location': 'nearby',
            }, (), b'', b'', 919293, [innerMessage])]
        self.expected = {0: {'BODYSTRUCTURE': [
            ['text', 'plain', ['key', 'value', 'name', 'thing'],
             'this-is-the-content-id', 'describing-the-content-goes-here!',
             '8BIT', '20', '4', '123456abcdef', ['inline', None], 'fr',
             'outer space'],
            'mixed', ['boundary', 'xyz'], None, 'en', 'nearby'
            ]}}
        return self._fetchWork(uid)

        L{IMAP4Client.fetchBodyStructure} can also parse the response to a
        I{FETCH BODYSTRUCTURE} command for a multipart message.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/mail/test/test_imap.py