private static function move_product( $product_id, $upgrader ) {
		$steps = self::get_state( 'steps' );
		if ( empty( $steps[ $product_id ]['unpacked_path'] ) ) {
			return new WP_Error( 'missing_unpacked_path', __( 'Could not find unpacked path.', 'woocommerce' ) );
		}

		$destination = 'plugin' === $steps[ $product_id ]['product_type']
			? WP_PLUGIN_DIR
			: get_theme_root();

		$package = array(
			'source'        => $steps[ $product_id ]['unpacked_path'],
			'destination'   => $destination,
			'clear_working' => true,
			'hook_extra'    => array(
				'type'   => $steps[ $product_id ]['product_type'],
				'action' => 'install',
			),
		);

		$result = $upgrader->install_package( $package );

		/**
		 * If install package returns error 'folder_exists' threat as success.
		 */
		if ( is_wp_error( $result ) && array_key_exists( self::$folder_exists, $result->errors ) ) {
			return array(
				self::$folder_exists => true,
				'destination'        => $result->error_data[ self::$folder_exists ],
			);
		}
		return $result;
	}