public function handleEdit($id, $key)
	{
		$column = $this->getColumn($key);
		$value = $this->getPresenter()->getRequest()->getPost('value');

		/**
		 * @var mixed Could be NULL of course
		 */
		$new_value = call_user_func_array($column->getEditableCallback(), [$id, $value]);

		$this->getPresenter()->payload->_datagrid_editable_new_value = $new_value;
	}