docstr: Create the main window and insert the custom frame.
docstr_tok: ["Create","the","main","window","and","insert","the","custom","frame","."]
code: def OnInit(self):
      """Create the main window and insert the custom frame."""
      self.Init()
      frame = CanvasFrame()
      frame.Show(True)
  
      return True
  
file_path: matplotlib/galleries/examples/user_interfaces/embedding_in_wx2_sgskip.py
imports: import wx
  import wx.lib.mixins.inspection
  import numpy
  from matplotlib.backends.backend_wxagg import FigureCanvasWxAgg
  from matplotlib.backends.backend_wxagg import NavigationToolbar2WxAgg
  from matplotlib.figure import Figure
label_desc: Use image node_id 1 for calling the App obj's underlying member method code with example usage: obj.OnInit() and returns: True