code: def on_draw(self, event):
      # clear the color buffer
      gloo.clear(color="white")
  
      for bar in self.bars:
          bar.draw()
  
file_path: vispy/examples/basics/visuals/colorbar_visual_types.py
imports: from vispy import app
  from vispy import gloo
  from vispy.visuals import ColorBarVisual
  from vispy.color import get_colormap
label_desc: Use image node_id 3 for calling the Canvas obj's underlying member method code with example usage: obj.on_draw(event) without return types