protected void add()

in model/src/main/java/jetbrains/jetpad/model/transform/Transformers.java [444:468]


      protected void add(ItemT item, CollectionT from, ObservableList<ItemT> to) {
        Iterator<ItemT> fromItr = from.iterator();
        int index = 0;
        boolean foundItem = false;
        for (ItemT curTo : to) {
          while (fromItr.hasNext()) {
            ItemT curFrom = fromItr.next();
            if (curFrom == curTo) {
              break;
            }
            if (curFrom == item) {
              foundItem = true;
              break;
            }
          }
          if (foundItem) {
            break;
          }
          index++;
        }
        if (!fromItr.hasNext() && !foundItem) {
          throw new IllegalStateException("item " + item + " has not been found in " + from);
        }
        to.add(index, item);
      }