public Iterable<? extends T> emptyOrFullIterableUndefined(long snap, AddressRange range,
			boolean forward) {
		return Collections.emptyList();
	}
The result of iteration when there is no view or space for the given range's space

<p>
Views composing undefiend units should return an iterable that generates (possibly caching)
undefined units. Others should leave this empty.

@param snap the snap the client requested
@param range the range of iteration
@param forward true to iterate forward (min to max), false for backward (max to min)
@return an iterable of units
Ghidra/Debug/Framework-TraceModeling/src/main/java/ghidra/trace/database/listing/AbstractBaseDBTraceCodeUnitsMemoryView.java