code: def test_canvas_ctor():
      assert isinstance(FigureCanvasBase().figure, Figure)
  
imports: import re
  from matplotlib import path, transforms
  from matplotlib.backend_bases import FigureCanvasBase, KeyEvent, LocationEvent, MouseButton, MouseEvent, NavigationToolbar2, RendererBase
  from matplotlib.backend_tools import RubberbandBase
  from matplotlib.figure import Figure
  from matplotlib.testing._markers import needs_pgf_xelatex
  import matplotlib.pyplot
  import numpy
  import pytest
label_desc: Use image node_id 2 for calling a global function with example usage: test_canvas_ctor() without return types