public function initTotals()
    {
        $parent = $this->getParentBlock();
        $this->_source = $parent->getSource();
        $total = new Varien_Object(
            array(
                'code' => 'adjust_adyen_fee_payment_fee',
                'block_name' => $this->getNameInLayout()
            )
        );

        // remove totals because you only want to show editable field
        $parent->removeTotal('payment_fee_excl');
        $parent->removeTotal('payment_fee_incl');

        $parent->addTotalBefore($total, 'agjustments'); // Yes, misspelled in Magento Core
        return $this;
    }