code: def __init__(self):
      fig.canvas.mpl_connect("button_press_event", self.on_press)
      fig.canvas.mpl_connect("button_release_event", self.on_release)
      fig.canvas.mpl_connect("motion_notify_event", self.on_move)
      self.x0, self.y0 = circ.center
      self.pressevent = None
  
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 1 to create a new EventHandler object  with example: obj = EventHandler()