code: JsonArray toJsonArray(){
          JsonArrayBuilder ab = Json.createArrayBuilder();
          ab.add(sku);
          ab.add(name);
          ab.add(category);
          ab.add(price);
          ab.add(quantity);
          
          return ab.build();        
      }
docs: Returns the value of this EcommerceItem as a JsonArray.
  @return this as a JsonArray