code: def on_release(self, event):
      self.pressevent = None
      self.x0, self.y0 = circ.center
  
file_path: matplotlib/galleries/examples/event_handling/looking_glass.py
imports: import matplotlib.pyplot
  import numpy
  import matplotlib.patches
label_desc: Use image node_id 3 for calling the EventHandler obj's underlying member method code with example usage: obj.on_release(event) without return types