Woocommerce disable free shipping in "big products"

wc-shipping-big-products.php

<?php
	if ( !class_exists( 'wcShippingBigProducts' ) ) {
		class wcShippingBigProducts {
      // disable free sipping if "big products" in cart
      // "big products" has shipping class 'productos-grandes'

			function activate() {
				add_filter( 'woocommerce_package_rates', array( $this, 'shippingBigProducts' ), 10, 2 );
			}

			function shippingBigProducts( $rates, $package ) {
				$has_big_products = false;
				foreach ( WC()->cart->get_cart() as $cart_item ) {
					$product = wc_get_product($cart_item['product_id']);
					if( $product->get_shipping_class() == 'productos-grandes'){
						$has_big_products = true;
						break;
					}
				}
				if($has_big_products){
					$new_rates = array();
					foreach ( $rates as $rate_id => $rate ) {
						if('free_shipping' !== $rate->method_id){
							$new_rates[$rate_id] = $rate;
						}
					}
					return $new_rates;
				}
				return $rates;
			}
		}

		$shipping_big_products = new wcShippingBigProducts();
		$shipping_big_products->activate();
	}