code: def zero_master_grads(master_params):
      for param in master_params:
          param.grad = None
  
imports: import numpy
  import torch
  import torch.nn
  from torch._utils import _flatten_dense_tensors, _unflatten_dense_tensors
  from .None import logger
label_desc: Use image node_id 10 for calling a global function with example usage: zero_master_grads(master_params) without return types