public function __construct() {
    // loading _wca.
    add_action( 'wp_head', array( $this, 'wp_head_top' ), 1 );

    // add to carts from non-product pages or lists -- search, store etc.
    add_action( 'wp_head', array( $this, 'loop_session_events' ), 2 );

    // loading s.js.
    add_action( 'wp_enqueue_scripts', array( $this, 'enqueue_tracking_script' ) );

    // Capture cart events.
    add_action( 'woocommerce_add_to_cart', array( $this, 'capture_add_to_cart' ), 10, 6 );

    // single product page view.
    add_action( 'woocommerce_after_single_product', array( $this, 'capture_product_view' ) );

    add_action( 'woocommerce_after_cart', array( $this, 'remove_from_cart' ) );
    add_action( 'woocommerce_after_mini_cart', array( $this, 'remove_from_cart' ) );
    add_action( 'wcct_before_cart_widget', array( $this, 'remove_from_cart' ) );
    add_filter( 'woocommerce_cart_item_remove_link', array( $this, 'remove_from_cart_attributes' ), 10, 2 );

    // Checkout.
    // Send events after checkout template (shortcode).
    add_action( 'woocommerce_after_checkout_form', array( $this, 'checkout_process' ) );
    // Send events after checkout block.
    add_action( 'woocommerce_blocks_enqueue_checkout_block_scripts_after', array( $this, 'checkout_process' ) );

    // order confirmed.
    add_action( 'woocommerce_thankyou', array( $this, 'order_process' ), 10, 1 );
    add_action( 'woocommerce_after_cart', array( $this, 'remove_from_cart_via_quantity' ), 10, 1 );
  }