if(next instanceof Literal) return ((Literal)next).getLiteral();
if(next instanceof LiteralValue) return ((LiteralValue)next).getValue().getStringValue();
    public String getLiteralValue() {    	if(steps.size() == 0)    		return "";    	Expression next = (Expression)steps.get(0);    	if(next instanceof Literal)    		return ((Literal)next).getLiteral();    	if(next instanceof PathExpr)    		return ((PathExpr)next).getLiteralValue();    	return "";    }