code: def print_png(self, fobj, *args, **kwargs):
      width, height = self.get_width_height()
  
      renderer = RendererCairo(self.figure.dpi)
      renderer.set_width_height(width, height)
      surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, width, height)
      renderer.set_ctx_from_surface(surface)
  
      self.figure.draw(renderer)
      surface.write_to_png(fobj)
  
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import six
  import gzip
  import sys
  import warnings
  import numpy
  from matplotlib.backend_bases import _Backend, FigureCanvasBase, FigureManagerBase, GraphicsContextBase, RendererBase
  from matplotlib.mathtext import MathTextParser
  from matplotlib.path import Path
  from matplotlib.transforms import Affine2D
  from matplotlib.font_manager import ttfFontProperty
label_desc: Use image node_id 1 for calling the FigureCanvasCairo obj's underlying member method code with example usage: obj.print_png(fobj) without return types