Grid_Basic::addButton PHP Method

    public function addButton($label, $class = 'Button')
    {
        if (!$this->buttonset) {
            $this->buttonset = $this->add('ButtonSet', null, 'grid_buttons')->setClass('atk-actions');
        }
        return $this->buttonset->add($class, 'gbtn' . count($this->elements))->set($label);
    }