`nbest_size < 0`: assuming that nbest_size is infinite and samples from the all hypothesis (lattice) using forward-filtering-and-backward-sampling algorithm. - `alpha`: Smoothing parameter for unigram sampling, and dropout probability of merge operations for BPE-dropout. Attributes: sp_model (`SentencePieceProcessor`): The *SentencePiece* processor that is used for every conversion (string, tokens and IDs). whitespaces (`set`): The whitespaces that are replaced in the whitespace normalization in preprocessing. non_printing_characters_re (`Pattern`): The compiled regular expression to remove non-printing characters in preprocessing. Z input_idsZattention_maskFNÚsp_model_kwargsÚ