def test_fetchSpecificMIME(self):
        """
        L{IMAP4Client.fetchSpecific}, when passed C{'MIME'} for C{headerType},
        sends the I{BODY[MIME]} command.  It returns a L{Deferred} which fires
        with a C{dict} mapping message sequence numbers to C{list}s of
        corresponding message data given by the server's response.
        """
        d = self.client.fetchSpecific('8', headerType='MIME')
        self.assertEqual(
            self.transport.value(), b'0001 FETCH 8 BODY[MIME]\r\n')
        self.client.lineReceived(b'* 8 FETCH (BODY[MIME] "Some body")')
        self.client.lineReceived(b'0001 OK FETCH completed')
        self.assertEqual(
            self.successResultOf(d),
            {8: [['BODY', ['MIME'], "Some body"]]})

        L{IMAP4Client.fetchSpecific}, when passed C{'MIME'} for C{headerType},
        sends the I{BODY[MIME]} command.  It returns a L{Deferred} which fires
        with a C{dict} mapping message sequence numbers to C{list}s of
        corresponding message data given by the server's response.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/mail/test/test_imap.py