Determines slotInParent from the ERD of the infoset element arg.
Determines slotInParent from the ERD of the infoset element arg. Hooks up the parent pointer of the new child to reference this.
When slot contains an array, this appends to the end of the array.
Retrieve the schema component that gave rise to this infoset item.
Retrieve the schema component that gave rise to this infoset item.
The totalElementCount is the total count of how many elements this InfosetItem contains.
The totalElementCount is the total count of how many elements this InfosetItem contains.
(Used to call this 'size', but size is often a length-like thing, so changed name to be more distinctive)