code: def on_draw(self, event):
      gloo.clear()
      # Draw
      self.program.draw("points")
      # Next iteration
      self._t = self.iteration(time.time() - self._t)
  
file_path: vispy/examples/demo/gloo/boids.py
imports: import time
  import numpy
  from scipy.spatial import cKDTree
  from vispy import gloo
  from vispy import app
label_desc: Use image node_id 6 for calling the Canvas obj's underlying member method code with example usage: obj.on_draw(event) without return types