code: def ragged_to_tensor_2axes_simple(
      rt: k2.RaggedTensor,
  ) -> Optional[torch.Tensor]:
      """Converts k2.RaggedTensor to torch.Tensor if the RaggedTensor is shallow (has two axes)."""
      rt_list = rt.tolist()
      result_list = []
      for e in rt_list:
          if len(e) == 0:
              result_list.append(0)
          elif len(e) == 1:
              result_list.append(e[0])
          else:
              return None
      return torch.tensor(result_list, dtype=torch.int32)
  
imports: import os
  import struct
  from pickle import UnpicklingError
  from typing import List, Optional, Tuple, Union
  import torch
  from nemo.core.utils.k2_guard import k2
  from nemo.utils import logging
label_desc: Use image node_id 5 for calling a global function with example usage: ragged_to_tensor_2axes_simple(rt) and returns: torch, None