code: function () {
              if ( this._cachedStartElementPath ) {
                  return this._cachedStartElementPath;
              }
              var start = this.getStart();
              if ( start ) {
                  return domUtils.findParents( start, true, null, true )
              }
              return [];
          }
docs: 获取选区开始位置的父节点到body
  @method getStartElementPath
  @return { Array } 返回父节点集合
  @example
  ```javascript
  editor.selection.getStartElementPath();
  ```