code: def reset_grad():
      d_optimizer.zero_grad()
      g_optimizer.zero_grad()
  
imports: import os
  import torch
  import torchvision
  import torch.nn
  from torchvision import transforms
  from torchvision.utils import save_image
label_desc: Use image node_id 2 for calling a global function with example usage: reset_grad() without return types