code: function () {
              var nativeSel, nativeRange;
              if ( this.isFocus() && (nativeSel = this.getNative()) ) {
                  nativeRange = browser.ie9below ? nativeSel.createRange() : nativeSel.getRangeAt( 0 );
                  return browser.ie9below ? nativeRange.text : nativeRange.toString();
              }
              return '';
          }
docs: 得到选区中的文本
  @method getText
  @return { String } 选区中包含的文本
  @example
  ```javascript
  editor.selection.getText();
  ```