CSPInstance {{ 
	public double valid(Solution solution){
		return 0;
	}
	public double quality(Solution solution){
		return 0;
	}
}}

CSPInstanceSet {{
        /** Is this a valid/well-formed Instance of the given instance? */
        public Option<String> belongsTo(Instance instance){
        	//...
        	return null;
        }        
        
        /** Is this a valid/well-formed InstanceSet? */
	    public Option<String> valid(){
	       //Semantic checks
	       return null;
	    }    
}}

Var {{ 
	public int compareTo(Var arg0) {
		// TODO Auto-generated method stub
		return 0;
	}
}}