@Override
	protected TaintSet whenNull(long offset) {
		String string = property.get(space.getAddress(offset));
		if (string == null) {
			return TaintSet.EMPTY;
		}
		return TaintSet.parse(string);
	}
{@inheritDoc}

<p>
The taint space will call this when the cache misses, allowing us to populate it with a taint
set stored in the trace. Note that if the emulator writes to this offset <em>before</em>
reading it, this will not get called for that offset. Here we simply get the string property
and parse the taint set.
Ghidra/Debug/TaintAnalysis/src/main/java/ghidra/pcode/emu/taint/trace/TaintTraceSpace.java