如何创建带有图像边框的透明圆形QWebEngineView？

from PyQt5.QtCore import Qt
from PyQt5.QtGui import QPainter, QPen, QPixmap
from PyQt5.QtWebEngineWidgets import QWebEngineView
from PyQt5.QtWidgets import QApplication, QMainWindow

class CustomWebEngineView(QWebEngineView):
    def paintEvent(self, event):
        # 调用父类的paintEvent方法
        super().paintEvent(event)
        
        # 创建QPainter对象
        painter = QPainter(self)
        
        # 设置抗锯齿渲染
        painter.setRenderHint(QPainter.Antialiasing)
        
        # 设置画笔颜色和宽度
        pen = QPen(Qt.red)
        pen.setWidth(2)
        painter.setPen(pen)
        
        # 绘制圆形边框
        painter.drawEllipse(self.rect())

class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        
        # 创建自定义的QWebEngineView子类实例
        self.webview = CustomWebEngineView(self)
        
        # 设置窗口标题和大小
        self.setWindowTitle("Transparent Circular QWebEngineView")
        self.setGeometry(100, 100, 800, 600)
        
        # 将自定义的QWebEngineView子类实例设置为主窗口的中央部件
        self.setCentralWidget(self.webview)

if __name__ == "__main__":
    app = QApplication([])
    window = MainWindow()
    window.show()
    app.exec_()