code: def main():
      # fiber.init(image="fiber-pytorch:latest")
      ring = Ring(2, pytorch_run_sgd, pytorch_ring_init)
      ring.run()
  
imports: import math
  import random
  import time
  import torch
  import torch.distributed
  import torch.nn
  import torch.nn.functional
  import torch.optim
  import torchvision.datasets
  import torchvision.transforms
  import fiber
  from fiber.experimental import Ring
label_desc: Use image node_id 5 for calling a global function with example usage: main() without return types