<a href={'/product/${product._id}'}>
<Card.Img src={product.image}/>
</a>
class Product extends Component{
handleUpVote(id) {
this.props.onVote(id)
}
...
<Product
key={'product-'+product.id}
id={product.id}
onVote={() => this.handleProductUpVote(product.id)}
/>
}