onTab(e) {
    if (this.props.onTab) {
      this.props.onTab(e);
      return;
    }
    const { editorState } = this.props;
    const newEditorState = RichUtils.onTab(e, editorState, 2);
    if (newEditorState !== editorState) {
      this.onChange(newEditorState);
    }
  }
Implemented to provide nesting of upto 2 levels in ULs or OLs.