code: def __enter__(self):
      self._context = "build"
      self.drawing_calls = []
      return self
  
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 2 for calling the Canvas obj's underlying member method code with example usage: obj.__enter__() and returns: self