class CategorizedString extends CategorizedLegend<String> {

    @Override
    public String getFromLower(Double d){
        if(d==null){
            throw new NullPointerException("The input threshold must not be null");
        }
        if(parameter instanceof StringLiteral){
            return ((StringLiteral) parameter).getValue(null);
        } else {
            String col = get(d);
            if(col == null){
                Categorize2String c2s = (Categorize2String) parameter;
                Map<String,Object> inp = new HashMap<>();
                inp.put(getField(), d);
                return c2s.getValue(inp);
            } else {
                return col;
            }
        }
    }

    public  CategorizedString(StringParameter sp);

}