code: def is_fsdp_model(model):
      if isinstance(model, FSDP):
          return True
      if hasattr(model, "trunk") and isinstance(model.trunk, FSDP):
          return True
      return False
  
file_path: vissl/vissl/utils/fsdp_utils.py
imports: import torch.distributed
  import torch.nn
  from fairscale.nn import auto_wrap, default_auto_wrap_policy, enable_wrap
  from fairscale.nn.data_parallel import auto_wrap_bn, FullyShardedDataParallel
  from vissl.config.attr_dict import AttrDict
label_desc: Use image node_id 4 for calling a global function with example usage: is_fsdp_model(model) and returns: False, True, True