code: def on_draw(self, event):
      gl.glClear(gl.GL_COLOR_BUFFER_BIT | gl.GL_DEPTH_BUFFER_BIT)
      gl.glDrawElements(
          gl.GL_TRIANGLES,
          self.icube_data.size,
          gl.GL_UNSIGNED_INT,
          None,
      )
  
file_path: vispy/examples/gloo/gl/cube.py
imports: import math
  import numpy
  from vispy import app
  from vispy.gloo import gl
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