found. If value is None the matched items are deleted, otherwise they are edited.
$+val If no match if found (see '$val'), the value is appended to the array. If any match is found nothing
is changed. A value of None has not sense.
found. If value is None the matched items are deleted, otherwise they are edited.
$+val If no match if found (see '$val'), the value is appended to the array. If any match is found nothing
is changed. A value of None has not sense.