public function addBonus(float $bonus, string $usergroup = ''): void
    {
        $this->bonus->setValue($bonus, $usergroup);
    }
public function addBonus(float $bonus, string $usergroup = ''): void
    {
        $this->bonus->setValue($bonus, $usergroup);
    }
public function addBonus ( float $ bonus , string $ usergroup = '' ) : void { $ this -> bonus -> setValue ( $ bonus , $ usergroup ) ; }
Shortcut to easily add the bonus of the item. The value must be a numeric.

@param float $bonus The bonus value of the item.
@param string $usergroup The usergroup of the bonus value.
Shortcut to easily add the bonus of the item . The value must be a numeric .