protected function get_object_subtotal() {
		if ( is_a( $this->object, 'WC_Cart' ) ) {
			return wc_add_number_precision( $this->object->get_displayed_subtotal() );
		} elseif ( is_a( $this->object, 'WC_Order' ) ) {
			$subtotal = wc_add_number_precision( $this->object->get_subtotal() );

			if ( $this->object->get_prices_include_tax() ) {
				// Add tax to tax-exclusive subtotal.
				$subtotal = $subtotal + wc_add_number_precision( round( $this->object->get_total_tax(), wc_get_price_decimals() ) );
			}

			return $subtotal;
		} else {
			return array_sum( wp_list_pluck( $this->items, 'price' ) );
		}
	}