def append(self, mailbox, message, flags = (), date = None):
        """Add the given message to the given mailbox.

        This command is allowed in the Authenticated and Selected states.

        @type mailbox: C{str}
        @param mailbox: The mailbox to which to add this message.

        @type message: Any file-like object
        @param message: The message to add, in RFC822 format.  Newlines
        in this file should be \\r\\n-style.

        @type flags: Any iterable of C{str}
        @param flags: The flags to associated with this message.

        @type date: C{str}
        @param date: The date to associate with this message.  This should
        be of the format DD-MM-YYYY HH:MM:SS +/-HHMM.  For example, in
        Eastern Standard Time, on July 1st 2004 at half past 1 PM,
        \"01-07-2004 13:30:00 -0500\".

        @rtype: C{Deferred}
        @return: A deferred whose callback is invoked when this command
        succeeds or whose errback is invoked if it fails.
        """
        message.seek(0, 2)
        L = message.tell()
        message.seek(0, 0)
        fmt = '%s (%s)%s {%d}'
        if date:
            date = date % ' "%s"'
        else:
            date = ''
        cmd = fmt % (
            _prepareMailboxName(mailbox), ' '.join(flags),
            date, L
        )
        d = self.sendCommand(Command('APPEND', cmd, (), self.__cbContinueAppend, message))
        return d
dataset/ETHPy150Open nlloyd/SubliminalCollaborator/libs/twisted/mail/imap4.py/IMAP4Client.append/swapped operands of `%`