code: def _load_bitmap(filename):
      
  
      basedir = os.path.join(rcParams['datapath'],'images')
  
      bmpFilename = os.path.normpath(os.path.join(basedir, filename))
      if not os.path.exists(bmpFilename):
          raise IOError('Could not find bitmap file "%s"; dying'%bmpFilename)
  
      bmp = wx.Bitmap(bmpFilename)
      return bmp
docs: Load a bitmap file from the backends/images subdirectory in which the
      matplotlib library is installed. The filename parameter should not
      contain any path information as this is determined automatically.
  
      Returns a wx.Bitmap object