code: def requires_grad(model, flag=True):
      mx_params = model.collect_params()
      for p in mx_params:
          if flag:
              mx_params[p].grad_req = "write"
          else:
              mx_params[p].grad_req = "null"
  
imports: import os
  import random
  import math
  import argparse
  import logging
  import os.path
  from io import BytesIO
  import lmdb
  import numpy
  from PIL import Image
  from tqdm import tqdm
  from mpl_toolkits.axes_grid1 import ImageGrid
  import matplotlib.pyplot
  import mxnet
  import mxnet.ndarray
  from mxnet import gluon, autograd
  from mxnet.gluon.data.vision import transforms
  from mxnet.gluon.data import DataLoader
  from model import StyledGenerator, Discriminator
label_desc: Use image node_id 1 for calling a global function with example usage: requires_grad(model, flag) without return types