public class Name {
        private Name(String name, int flag){...}
    
        public static Name asMissing(){new Name(null, -1);}
        public static Name asNotApplicable(){new Name(null, -2);}    
        public static Name asNotAvailableYet(){new Name(null, -3);}        
        public static Name asForbidden(){new Name(null, -4);}        
        public static Name create(String name){new Name(name, 0)}
        
        public boolean isMissing(){flag==-1}
        public boolean isNotApplicable(){flag==-2}
        public boolean isNotAvailableYet(){flag==-3}
        public boolean isForbidden(){flag==-4}
        public String get() {if (flag!=0) throw new Exception(flag) else name}
    }