public function addClass(string $value) : self
    {
        $class = trim($this->attributes['class']);
        $this->attributes['class'] = trim($class . ' ' . trim($value));
        return $this;
    }
public function addClass(string $value) : self
    {
        $class = trim($this->attributes['class']);
        $this->attributes['class'] = trim($class . ' ' . trim($value));
        return $this;
    }
public function addClass ( string $ value ) : self { $ class = trim ( $ this -> attributes [ 'class' ] ) ; $ this -> attributes [ 'class' ] = trim ( $ class . ' ' . trim ( $ value ) ) ; return $ this ; }
Add the specified class to the class attribute for the form field.

@param string $value A class to add

@return self
Add the specified class to the class attribute for the form field .