code: def save_imgs(x, fname):
      """Helper method to save a grid of images to a PNG file.
  
      Args:
        x: A numpy array of shape [n_images, height, width].
        fname: The filename to write to (including extension).
      """
      n = x.shape[0]
      fig = figure.Figure(figsize=(n, 1), frameon=False)
      canvas = backend_agg.FigureCanvasAgg(fig)
      for i in range(n):
          ax = fig.add_subplot(1, n, i + 1)
          ax.imshow(
              x[i].squeeze(),
              interpolation="none",
              cmap=cm.get_cmap("binary"),
          )
          ax.axis("off")
      canvas.print_figure(fname, format="png")
      print("saved %s" % fname)
  
imports: import functools
  import os
  import time
  from absl import flags
  from matplotlib import cm
  from matplotlib import figure
  from matplotlib.backends import backend_agg
  import numpy
  from six.moves import urllib
  import tensorflow.compat.v1
  from tensorflow_probability import distributions
  from tensorflow_probability.python.internal import tf_keras
  from tensorflow.contrib.learn.python.learn.datasets import mnist
  from tensorflow.python.training import moving_averages
label_desc: Use image node_id 4 for calling a global function with example usage: save_imgs(x, fname) without return types