code: def __init__(self):
      self._context = None
      self.theme = DEFAULT_THEME
      self.figure = None
      self.backend = matplotlib.get_backend()
      self.drawing_calls = []
      self.theme = DEFAULT_THEME
  
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 1 to create a new Canvas object  with example: obj = Canvas()