public function exists($key)
    {
        $index = explode('.', $key);
        self::getValue($this->item, $index, false, $err);
        
        return !$err;
    }
public function exists($key)
    {
        $index = explode('.', $key);
        self::getValue($this->item, $index, false, $err);
        
        return !$err;
    }
public function exists ( $ key ) { $ index = explode ( '.' , $ key ) ; self :: getValue ( $ this -> item , $ index , false , $ err ) ; return ! $ err ; }
Check if property exists

@param string $key The index to fetch in dot notation
@return boolean
Check if property exists