def METHOD_NAME(self, sentence: str, *addl_sentences, no_separator=True) -> torch.LongTensor:
    """
    BPE-encode a sentence (or multiple sentences).
    Every sequence begins with a beginning-of-sentence (`<s>`) symbol.
    Every sentence ends with an end-of-sentence (`</s>`).
    Example (single sentence): `<s> a b c </s>`
    Example (sentence pair): `<s> d e f </s> 1 2 3 </s>`
    The BPE encoding follows GPT-2. One subtle detail is that the GPT-2 BPE
    requires leading spaces. For example::
        >>> bart.encode('Hello world').tolist()
        [0, 31414, 232, 2]
        >>> bart.encode(' world').tolist()
        [0, 232, 2]
        >>> bart.encode('world').tolist()
        [0, 8331, 2]
    """
    tokens = self.bpe.METHOD_NAME(sentence)
    if len(tokens.split(' ')) > self.max_positions - 2:
        tokens = ' '.join(tokens.split(' ')[:self.max_positions - 2])
    bpe_sentence = '<s> ' + tokens + ' </s>'
    for s in addl_sentences:
        bpe_sentence += (' </s>' if not no_separator else '')
        bpe_sentence += ' ' + self.bpe.METHOD_NAME(s) + ' </s>'
    tokens = self.task.source_dictionary.encode_line(bpe_sentence, append_eos=False)
    return tokens.long()