code: def key_release_event(self, widget, event):
      KeyEvent(
          "key_release_event",
          self,
          self._get_key(event),
          *self._mpl_coords(),
          guiEvent=event,
      )._process()
      return True
  
imports: import functools
  import logging
  import os
  from pathlib import Path
  import matplotlib
  from matplotlib import _api, backend_tools, cbook
  from matplotlib.backend_bases import ToolContainerBase, CloseEvent, KeyEvent, LocationEvent, MouseEvent, ResizeEvent
  from gi.repository import Gio, GLib, GObject, Gtk, Gdk
  from .None import _backend_gtk
  from ._backend_gtk import _BackendGTK, _FigureCanvasGTK, _FigureManagerGTK, _NavigationToolbar2GTK, TimerGTK
label_desc: Use image node_id 9 for calling the FigureCanvasGTK3 obj's underlying member method code with example usage: obj.key_release_event(widget, event) and returns: True