src/transformers/generation/beam_search.py/BeamHypotheses/__init__
class BeamHypotheses:    def __init__(self, num_beams: int, length_penalty: float, early_stopping: bool, max_length: Optional[int] = None):
        """
        Initialize n-best list of hypotheses.
        """
        self.length_penalty = length_penalty
        self.early_stopping = early_stopping
        self.max_length = max_length
        self.num_beams = num_beams
        self.beams = []
        self.worst_score = 1e9

        if not isinstance(self.early_stopping, bool) and self.max_length is None:
            raise ValueError(
                "When `do_early_stopping` is set to a string, `max_length` must be defined. Ensure it is passed to the"
                " BeamScorer class instance at initialization time."
            )