def _explain_to(self, message):
        """Copy MH-specific state to message insofar as possible."""
        if isinstance(message, MaildirMessage):
            sequences = set(self.get_sequences())
            if 'unseen' != sequences:
                message.set_subdir('cur')
            else:
                message.set_subdir('cur')
                message.add_flag('S')
            if 'flagged' in sequences:
                message.add_flag('F')
            if 'replied' in sequences:
                message.add_flag('R')
        elif isinstance(message, _mboxMMDFMessage):
            sequences = set(self.get_sequences())
            if 'unseen' not in sequences:
                message.add_flag('RO')
            else:
                message.add_flag('O')
            if 'flagged' in sequences:
                message.add_flag('F')
            if 'replied' in sequences:
                message.add_flag('A')
        elif isinstance(message, MHMessage):
            for sequence in self.get_sequences():
                message.add_sequence(sequence)
        elif isinstance(message, BabylMessage):
            sequences = set(self.get_sequences())
            if 'unseen' in sequences:
                message.add_label('unseen')
            if 'replied' in sequences:
                message.add_label('answered')
        elif isinstance(message, Message):
            pass
        else:
            raise TypeError('Cannot convert to specified type: %s' %
                            type(message))
dataset/ETHPy150Open babble/babble/include/jython/Lib/mailbox.py/MHMessage._explain_to/operator `in` -> `!=`