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: from abc import ABC, abstractmethod
  from collections import UserDict
  from typing import Dict, List, Optional, Tuple, Union
  import numpy
  import torch
  from ..utils import add_start_docstrings
  from .beam_constraints import Constraint, ConstraintListState
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