React-native-deck-swiper: ref is not working

[Nisthar]

ref is not working. Its returning undefined

 <Swiper
          ref={swiper => {
            this.swiper = swiper;
          }}
          cards={this.state.cards}
          renderCard={card => {
            return <Card {...card} />;
          }}
          onSwipedAll={() => {
            console.log("onSwipedAll");
          }}
          cardIndex={0}
          backgroundColor={"#fff"}
          cardVerticalMargin={0}
          cardHorizontalMargin={0}
          childrenOnTop={false}
          horizontalThreshold={200}
/>

[IsaacWIvins]

Instead of this.refs.swiper try calling this.swiper