@Override
	public FieldLocation getFieldLocation(ListingField bf, BigInteger index, int fieldNum,
			ProgramLocation programLoc) {
		if (!(programLoc instanceof CommentFieldLocation)) {
			return null;
		}

		CommentFieldLocation loc = (CommentFieldLocation) programLoc;
		if (loc.getCommentType() != CommentType.POST) {
			return null;
		}
		return new FieldLocation(index, fieldNum, loc.getRow(), loc.getCharOffset());
	}
@see ghidra.app.util.viewer.field.FieldFactory#getFieldLocation(ghidra.app.util.viewer.field.ListingField, BigInteger, int, ghidra.program.util.ProgramLocation)
Ghidra/Features/Base/src/main/java/ghidra/app/util/viewer/field/PostCommentFieldFactory.java