How to override Woocoomerce class-wc-cart?

Question

WooCommerce

Can't override class-wc-cart or add_to_cart method. Tried like this:
1.

add_action( 'woocommerce_add_to_cart', 'add_to_cart', 20, 0 );
function add_to_cart( $product_id = 0, $quantity = 1, $variation_id = 0, $variation = array(), $cart_item_data = array() ) {
//code
}

2. Make a folder in the theme includes/class-wc-cart.php
3. Override the method

function add_to_cart( $product_id = 0, $quantity = 1, $variation_id = 0, $variation = array(), $cart_item_data = array() ) {
//code
}