如何找到被点击的QComboBox的下拉箭头？

from PyQt5.QtWidgets import QApplication, QMainWindow, QComboBox
from PyQt5.QtCore import Qt

class MyWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        self.initUI()
        
    def initUI(self):
        self.comboBox = QComboBox(self)
        self.comboBox.addItems(["Item 1", "Item 2", "Item 3"])
        self.comboBox.activated.connect(self.onComboBoxActivated)

    def onComboBoxActivated(self, index):
        arrowRect = self.comboBox.rect().adjusted(self.comboBox.width() - 20, 0, 0, 0)
        if arrowRect.contains(self.comboBox.mapFromGlobal(QApplication.instance().cursor().pos())):
            print("Arrow clicked")

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