@Override
	public FieldLocation getFieldLocation(ListingField listingField, BigInteger index, int fieldNum,
			ProgramLocation programLoc) {

		if (programLoc instanceof FunctionTagFieldLocation) {
			FunctionTagFieldLocation fieldLocation = (FunctionTagFieldLocation) programLoc;
			return new FieldLocation(index, fieldNum, 0, fieldLocation.getCharOffset());
		}
		return null;
	}
Overridden to ensure that we only place function tag text on the header of a 
function.
Ghidra/Features/Base/src/main/java/ghidra/app/util/viewer/field/FunctionTagFieldFactory.java