Workaround to prevent Chrome from causing QClipboard::dataChanged() was called twice

#I write the slot of QClipboard::dataChanged() as this  to avoid the bug,
@pyqtSlot()
def detectClipboardUrl(self):
    clipboardText = self.clipboard.text()
    if getattr(self.clipboard, 'lastClipboardUrl', None) != clipboardText:
        url = clipboardText
        setattr(self.clipboard, 'lastClipboardUrl', url)
        QTimer.singleShot(400, lambda:setattr(self.clipboard, 'lastClipboardUrl', None))#the interval of successive call of this slot is less than 400ms, after 400ms this line would allow you copy the same Text again