code: private void init() {
          // defaults for interface with page author
          begin_ = null;          // (no expression)
          end_ = null;            // (no expression)
          step_ = null;           // (no expression)
          items_ = null;        // (no expression)
          delims_ = null;        // (no expression)
      }
docs: (re)initializes state (during release() or construction)