code: Item newClassItem(final String value) {
          Item result = get(key2.set(CLASS, value, null, null));
          if (result == null) {
              pool.putBS(CLASS, newUTF8(value));
              result = new Item(poolIndex++, key2);
              put(result);
          }
          return result;
      }
docs: Adds a class reference to the constant pool of the class being build. Does nothing if the constant pool already
  contains a similar item.
  <i>This method is intended for {@link Attribute} sub classes, and is normally not needed by class generators or
  adapters.</i>
  
  @param value the internal name of the class.
  @return a new or already existing class reference item.