code: def flatten_dict(nested: Dict, sep: str = "/") -> Dict:
      """Flatten dictionary and concatenate nested keys with separator."""
  
      def recurse(nest: Dict, prefix: str, into: Dict) -> None:
          for k, v in nest.items():
              if sep in k:
                  raise ValueError(
                      f"separator '{sep}' not allowed to be in key '{k}'"
                  )
              if isinstance(v, Mapping):
                  recurse(v, prefix + k + sep, into)
              else:
                  into[prefix + k] = v
  
      flat = {}
      recurse(nested, "", flat)
      return flat
  
imports: import gc
  import random
  import warnings
  from contextlib import contextmanager
  from typing import Dict, List, Optional, Tuple, Union
  import numpy
  import torch
  import torch.nn
  import torch.nn.functional
  from torch.nn.utils.rnn import pad_sequence
  from transformers import top_k_top_p_filtering
  from .import_utils import is_npu_available, is_xpu_available
label_desc: Use image node_id 1 for calling a global function with example usage: flatten_dict(nested, sep) and returns: flat