protected function length_helper($data){
	    if ( ($this->min || $this->max) && $this->length_helper ){
            $notice = [];
            $class_name = 'ok';
            if( $this->min ){
                $notice[] = sprintf($this->__('%s chars or more'), number_format($this->min));
                if( $this->min > mb_strlen($data, 'utf-8') ){
                    $class_name = 'ng';
                }
            }
            if( $this->max ){
                $notice[] = sprintf($this->__('%s chars or less'), number_format($this->max));
                if( $this->max < mb_strlen($data, 'utf-8') ){
                    $class_name = 'ng';
                }
            }

            return sprintf('<p class="char-counter %s"><i class="dashicons"></i> <strong>%s</strong><span> %s</span><small>%s</small></p>',
                $class_name, mb_strlen($data, 'utf-8'), $this->__('Letters'), implode(', ', $notice));
        }else{
            return '';
        }
    }