src/cart/AbstractCartPosition.php
protected function serializationMap()
    {
        return [
            'attributes' => $this->getAttributes(),
            '_quantity' => $this->_quantity,
            '_price' => $this->_price,
            '_value' => $this->_value,
            '_id' => $this->_id,
        ];
    }
protected function serializationMap()
    {
        return [
            'attributes' => $this->getAttributes(),
            '_quantity' => $this->_quantity,
            '_price' => $this->_price,
            '_value' => $this->_value,
            '_id' => $this->_id,
        ];
    }
protected function serializationMap ( ) { return [ 'attributes' => $ this -> getAttributes ( ) , '_quantity' => $ this -> _quantity , '_price' => $ this -> _price , '_value' => $ this -> _value , '_id' => $ this -> _id , ] ; }
Method stores map of attributes that must be serialized.

@return array key is the attribute name where the value should be extracted
In case when the value shoule be assigned in a special way, use [[unserializationMap]]
to map key to a closure, that will set the value

@see unserializationMap
Method stores map of attributes that must be serialized .