docstr: Number of hypotheses in the list.
code: def __len__(self):
      """
      Number of hypotheses in the list.
      """
      return len(self.hyp)
  
imports: import torch
  from torch import nn
  from torch.nn import functional
  from transformers.models.bart.configuration_bart import BartConfig
  from .modeling_bart import BartModel
  from ..utils.util import avg_token_embeddings, seq_to_mask, get_model_device
  from functools import partial
  from typing import Union
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