testSameParentAnyOrCustomElement function
Returns true if the entry has the same parent as the given parentId and is an "Any" or a custom range entry.
Implementation
bool testSameParentAnyOrCustomElement(SelectEntry e, String parentId) =>
(e as SelectChildEntry).parentId == parentId &&
(e.isAny || (e is SelectRangeEntry && e.isCustom));