code: def save(self, file_name):
      self.figure.savefig(file_name)
  
imports: import itertools
  import math
  import numpy
  import matplotlib
  import matplotlib.pyplot
  import IPython.display
  from mpl_toolkits.mplot3d import Axes3D
  from matplotlib.collections import PolyCollection
label_desc: Use image node_id 6 for calling the Canvas obj's underlying member method code with example usage: obj.save(file_name) without return types