/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package debugoff;

import static java.lang.System.out;
 /**
 *
 * @author alice
 */
public class Debugoff{
 
     public String debug(){
        String pippo;
        pippo="Errore";
        return pippo;
        }
    
      public String stampaDebug(){
         return "Esiste un "+debug();
     }
}

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package debugoff;

import static java.lang.System.out;
 /**
 *
 * @author alice
 */
public class Debugoff{
 
     public String debug(){
        String pippo;
        pippo="Errore";
        return pippo;
        }
 
}

Update Debugoff.java