def METHOD_NAME(self, raise_on_busy: bool = True) -> bool:
    """
    Umount by the mountpoint directory
    Wait up to 10sec trying to umount. If the resource stays
    busy the call will raise an exception unless raise_on_busy
    is set to False. In case the umount failed and raise_on_busy
    is set to False, the method returns False to indicate the
    error condition.
    :return: True or False
    :rtype: bool
    """
    if self.is_mounted():
        umounted_successfully = False
        for busy in range(0, 10):
            try:
                Command.run(['umount', self.mountpoint])
                umounted_successfully = True
                break
            except Exception:
                log.warning(
                    '%d umount of %s failed, try again in 1sec',
                    busy, self.mountpoint
                )
                time.sleep(1)
        if not umounted_successfully:
            if raise_on_busy:
                lsof = Path.which('lsof', access_mode=os.X_OK)
                if lsof:
                    open_files = Command.run(
                        [lsof, '+c', '0', self.mountpoint],
                        raise_on_error=False
                    )
                    open_files_info = 'Open files status:{0}{1}'.format(
                        os.linesep, open_files.output
                    )
                else:
                    open_files_info = 'For further details install: lsof'
                message = dedent('''\n
                    Failed to umount: {0}.
                    Your build host system is in an inconsistent state.
                    The cleanup of the created resource was not possible
                    because it is still busy. This resource and all nested
                    resources stays active on your host and needs a manual
                    cleanup.
                    Please do not use the intermediate state of the image
                    files created so far. There is no guarantee that the
                    produced results are valid.
                    {1}
                ''')
                raise KiwiUmountBusyError(
                    message.format(self.mountpoint, open_files_info)
                )
            else:
                log.warning(
                    '{0} still busy at {1}'.format(
                        self.mountpoint, type(self).__name__
                    )
                )
                # skip removing the mountpoint directory
                return False
    return True