code: def set_foreground(self, fg, isRGBA=None):
      GraphicsContextBase.set_foreground(self, fg, isRGBA)
      if len(self._rgb) == 3:
          self.ctx.set_source_rgb(*self._rgb)
      else:
          self.ctx.set_source_rgba(*self._rgb)
  
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 8 for calling the GraphicsContextCairo obj's underlying member method code with example usage: obj.set_foreground(fg, isRGBA) without return types