@Override
	public void restoreState(Program p, SaveState obj) {
		super.restoreState(p, obj);
		rep = obj.getString("_REP", "");
		subOpIndex = obj.getInt("_SUBOPINDEX", subOpIndex);
	}
Returns the sub operand index at this location.
<p>
This index can be used on the instruction.getOpObjects() to find the actual object (Address,
Register, Scalar) the cursor is over.
@return 0-n if over a valid OpObject, -1 otherwise
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/util/OperandFieldLocation.java