如何删除绘图和导航工具栏之间的边框？(带有wx的matplotlib)

import matplotlib.pyplot as plt
from matplotlib.backends.backend_wxagg import FigureCanvasWxAgg as FigureCanvas
from matplotlib.figure import Figure

import wx

class MyFrame(wx.Frame):
    def __init__(self, parent, title):
        super(MyFrame, self).__init__(parent, title=title, size=(800, 600))

class MyPanel(wx.Panel):
    def __init__(self, parent):
        super(MyPanel, self).__init__(parent)

        self.figure = Figure()
        self.axes = self.figure.add_subplot(111)

        self.canvas = FigureCanvas(self, -1, self.figure)

        sizer = wx.BoxSizer(wx.VERTICAL)
        sizer.Add(self.canvas, 1, wx.EXPAND)
        self.SetSizer(sizer)

    def remove_toolbar_border(self):
        toolbar = self.canvas.toolbar
        toolbar.SetBackgroundColour(wx.NullColour)
        toolbar.SetForegroundColour(wx.NullColour)
        toolbar.SetBorderLineSize(0)
        toolbar.SetToolBitmapSize((1, 1))

        self.panel.remove_toolbar_border()

if __name__ == '__main__':
    app = wx.App()
    frame = MyFrame(None, "Matplotlib with wxPython")
    frame.Show()
    app.MainLoop()