code: boolean isInlineRule( CssFormatter formatter ) {
          if( selectors.length == 1 && selectors[0].equals( "&" ) ) {
              return hasOnlyInlineProperties( formatter );
          }
          return false;
      }
docs: If there is only a special selector "&" and also all subrules have only this special selector.
  
  @param formatter current formatter
  @return true, if selector is "&"