code: public int newField(
              final String owner,
              final String name,
              final String desc) {
          Item result = get(key3.set(FIELD, owner, name, desc));
          if (result == null) {
              put122(FIELD, newClass(owner), newNameType(name, desc));
              result = new Item(poolIndex++, key3);
              put(result);
          }
          return result.index;
      }
docs: Adds a field 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 owner the internal name of the field's owner class.
  @param name the field's name.
  @param desc the field's descriptor.
  @return the index of a new or already existing field reference item.