@Override
	public boolean equals(Object obj ){
	   boolean result = false;
	   if(this ==  obj)
		   return true;
	   if(!(obj  instanceof ConcreteItem)){
		  return false;   
	   }
	   ConcreteItem item =  (ConcreteItem)obj;
	   if(item.name.equals(this.name)
			   && item.price.equals(this.price)
			   && item.quantity == this.quantity){
		   result = true;
	   }
	return result;
	  	
	}