docstr: Use the mouse wheel to zoom.
code: def on_mouse_wheel(self, event):
      """Use the mouse wheel to zoom."""
      self.markers.transform.zoom(
          (1.25 ** event.delta[1],) * 2, center=event.pos
      )
      self.update()
  
file_path: vispy/examples/basics/visuals/markers.py
imports: import numpy
  from vispy import app, visuals
  from vispy.visuals.transforms import STTransform
label_desc: Use image node_id 3 for calling the Canvas obj's underlying member method code with example usage: obj.on_mouse_wheel(event) without return types