'Create this file with the given access mode, if it doesn\'t exist.'

def touch(self, mode=438, exist_ok=True):

    if self._closed:
        self._raise_closed()
    if exist_ok:
        try:
            self._accessor.utime(self, None)
        except OSError:
            pass
        else:
            return
    flags = (os.O_CREAT | os.O_WRONLY)
    if (not exist_ok):
        flags |= os.O_EXCL
    fd = self._raw_open(flags, mode)
    os.close(fd)
