public function add_rate( $args = array() ) {
		$args = apply_filters(
			'woocommerce_shipping_method_add_rate_args',
			wp_parse_args(
				$args,
				array(
					'id'             => $this->get_rate_id(), // ID for the rate. If not passed, this id:instance default will be used.
					'label'          => '', // Label for the rate.
					'cost'           => '0', // Amount or array of costs (per item shipping).
					'taxes'          => '', // Pass taxes, or leave empty to have it calculated for you, or 'false' to disable calculations.
					'calc_tax'       => 'per_order', // Calc tax per_order or per_item. Per item needs an array of costs.
					'meta_data'      => array(), // Array of misc meta data to store along with this rate - key value pairs.
					'package'        => false, // Package array this rate was generated for @since 2.6.0.
					'price_decimals' => wc_get_price_decimals(),
				)
			),
			$this
		);

		// ID and label are required.
		if ( ! $args['id'] || ! $args['label'] ) {
			return;
		}

		// Total up the cost.
		$total_cost = is_array( $args['cost'] ) ? array_sum( $args['cost'] ) : $args['cost'];
		$taxes      = $args['taxes'];

		// Taxes - if not an array and not set to false, calc tax based on cost and passed calc_tax variable. This saves shipping methods having to do complex tax calculations.
		if ( ! is_array( $taxes ) && false !== $taxes && $total_cost > 0 && $this->is_taxable() ) {
			$taxes = 'per_item' === $args['calc_tax'] ? $this->get_taxes_per_item( $args['cost'] ) : WC_Tax::calc_shipping_tax( $total_cost, WC_Tax::get_shipping_tax_rates() );
		}

		// Round the total cost after taxes have been calculated.
		$total_cost = wc_format_decimal( $total_cost, $args['price_decimals'] );

		// Create rate object.
		$rate = new WC_Shipping_Rate();
		$rate->set_id( $args['id'] );
		$rate->set_method_id( $this->id );
		$rate->set_instance_id( $this->instance_id );
		$rate->set_label( $args['label'] );
		$rate->set_cost( $total_cost );
		$rate->set_taxes( $taxes );

		if ( ! empty( $args['meta_data'] ) ) {
			foreach ( $args['meta_data'] as $key => $value ) {
				$rate->add_meta_data( $key, $value );
			}
		}

		// Store package data.
		if ( $args['package'] ) {
			$items_in_package = array();
			foreach ( $args['package']['contents'] as $item ) {
				$product            = $item['data'];
				$items_in_package[] = $product->get_name() . ' × ' . $item['quantity'];
			}
			$rate->add_meta_data( __( 'Items', 'woocommerce' ), implode( ', ', $items_in_package ) );
		}

		$this->rates[ $args['id'] ] = apply_filters( 'woocommerce_shipping_method_add_rate', $rate, $args, $this );
	}