code: def world_size(self):
      return 1
  
file_path: pytorch/test/distributed/fsdp/test_fsdp_input.py
imports: import sys
  import torch
  from torch import distributed
  from torch.distributed.fsdp import FullyShardedDataParallel
  from torch.nn import Linear, Module
  from torch.optim import SGD
  from torch.testing._internal.common_distributed import skip_if_lt_x_gpu
  from torch.testing._internal.common_fsdp import FSDPTest
  from torch.testing._internal.common_utils import instantiate_parametrized_tests, parametrize, run_tests, subtest, TEST_WITH_DEV_DBG_ASAN
label_desc: Use image node_id 1 for calling the TestInput obj's underlying member method code with example usage: obj.world_size() and returns: int