docstr: Number of hypotheses in the list.
docstr_tok: ["Number","of","hypotheses","in","the","list","."]
code: def __len__(self):
      """
      Number of hypotheses in the list.
      """
      return len(self.beams)
  
imports: import warnings
  from abc import ABC, abstractmethod
  from collections import UserDict
  from typing import List, Optional, Tuple
  import numpy
  import torch
  from .generation_beam_constraints import Constraint, ConstraintListState
  from .utils import add_start_docstrings
label_desc: Use image node_id 2 for calling the BeamHypotheses obj's underlying member method code with example usage: obj.__len__() and returns: len