code: def jit_step(x, weights):
      optim.zero_grad()
      loss = jit_mod(x)
      loss.backward()
      optim.step()
      return loss, None
  
file_path: pytorch/functorch/examples/compilation/linear_train.py
imports: import time
  import torch
  import torch.nn
  from functorch import make_functional
  from functorch.compile import nnc_jit
label_desc: Use image node_id 3 for calling a global function with example usage: jit_step(x, weights) and returns: loss,  None