class CategorizedReal extends CategorizedLegend<Double> {

    public void setParameter(RealParameter param) {
        if(param instanceof RealLiteral){
            parameter = param;
            fireTypeChanged();
        } else if(param instanceof Categorize2Real){
            RealParameter rp = ((Categorize2Real) param).getLookupValue();
            if(rp instanceof RealAttribute){
                parameter = param;
                field = ((RealAttribute) rp).getColumnName();
                fireTypeChanged();
            } else {
                throw new IllegalArgumentException("The given RealParameter instance can't be recognized as a " +
                        "valid CategorizedReal.");
            }
        } else {
            throw new IllegalArgumentException("The given RealParameter instance can't be recognized as a " +
                    "valid CategorizedReal.");
        }
    }

    public  CategorizedReal(RealParameter sp);

}