vate function validate_array_and_quote( array $items ) {
		$items_array = array_filter( $items, 'is_string' );

		return array_map(
			static function ( $item ) {
				return preg_quote( $item, '/' );
			},
			$items_array
		);
	}

	/**
	 * Check if database has at least one completed row.
	 *
	 * @return bool
	 */
	public function has_one_completed_row_at_least() {
		return $this->used_css_query->get_completed_count() > 0;
	}

	/**
	 * Process on submit jobs.
	 *
	 * @return void
	 */
	public function process_on_submit_jobs() {

		if ( ! $this->is_enabled() ) {
			$this->logger::debug( 'RUCSS: Stop processing cron iteration because option is disabled.' );

			return;
		}

		/**
		 * Pending rows cont.
		 *
		 * @param int $count Number of rows.
		 */
		$pending_job = (int) apply_filters( 'rocket_rucss_pending_jobs_cron_rows_count', 100 );

		/**
		 * Maximum processing rows.
		 *
		 * @param int $max Max processing rows.
		 */
		$max_pending_rows = (int) apply_filters( 'rocket_rucss_max_pending_jobs', 3 * $pending_job, $pending_job );
		$rows             = $this->used_css_query->get_on_submit_jobs( $max_pending_rows );

		foreach ( $rows as $row ) {
			$response = $this->send_api( $row->url, (bool) $row->is_mobile );
			if ( false === $response || ! isset( $response['contents'], $response['contents']['jobId'], $response['contents']['queueName'] ) ) {

				$this->used_css_query->make_status_failed( (int) $row->id, '',  '' );
				continue;
			}

			/**
			 * Lock preload URL.
			 *
			 * @param string $url URL to lock
			 */
			do_action( 'rocket_preload_lock_url', $row->url );

			$this->used_css_query->make_status_pending(
				(int) $row->id,
				$response['contents']['jobId'],
				$response['contents']['queueName'],
				(bool) $row->is_mobile
			);
		}
	}

	/**
	 * Send the job to the API.
	 *
	 * @param string $url URL to work on.
	 * @param bool   $is_mobile Is the page for mobile.
	 * @return array|false
	 */
	protected function send_api( string $url, bool $is_mobile ) {
		/**
		 * Filters the RUCSS safelist
		 *
		 * @since 3.11
		 *
		 * @param array $safelist Array of safelist values.
		 */
		$safelist = apply_filters( 'rocket_rucss_safelist', $this->options->get( 'remove_unused_css_safelist', [] ) );

		/**
		 * Filters the styles attributes to be skipped (blocked) by RUCSS.
		 *
		 * @since 3.14
		 *
		 * @param array $skipped_attr Array of safelist values.
		 */
		$skipped_attr = apply_filters( 'rocket_rucss_skip_styles_with_attr', [] );
		$skipped_attr = ( is_array( $skipped_attr ) ) ? $skipped_attr : [];

		$config = [
			'treeshake'      => 1,
			'rucss_safelist' => $safelist,
			'skip_attr'      => $skipped_attr,
			'is_mobile'      => $is_mobile,
			'is_home'        => $this->is_home( $url ),
		];

		$add_to_queue_response = $this->api->add_to_queue( $url, $config );
		if ( 200 !== $add_to_queue_response['code'] ) {
			$this->logger::error(
				'Error when contacting the RUCSS API.',
				[
					'rucss error',
					'url'     => $url,
					'code'    => $add_to_queue_response['code'],
					'message' => $add_to_queue_response['message'],
				]
			);

			return false;
		}

		return $add_to_queue_response;
	}
}
<br />
<b>Fatal error</b>:  Uncaught TypeError: Argument 3 passed to WP_Rocket\Engine\Optimization\RUCSS\Admin\Subscriber::__construct() must be an instance of WP_Rocket\Engine\Optimization\RUCSS\Controller\UsedCSS, string given in /home/merciket/public_html/wp-content/plugins/wp-rocket/inc/Engine/Optimization/RUCSS/Admin/Subscriber.php:49
Stack trace:
#0 [internal function]: WP_Rocket\Engine\Optimization\RUCSS\Admin\Subscriber-&gt;__construct(Object(WP_Rocket\Engine\Optimization\RUCSS\Admin\Settings), Object(WP_Rocket\Engine\Optimization\RUCSS\Admin\Database), 'WP_Rocket\\Engin...', Object(WP_Rocket\Engine\Optimization\RUCSS\Controller\Queue))
#1 /home/merciket/public_html/wp-content/plugins/wp-rocket/inc/Dependencies/League/Container/Definition/Definition.php(256): ReflectionClass-&gt;newInstanceArgs(Array)
#2 /home/merciket/public_html/wp-content/plugins/wp-rocket/inc/Dependencies/League/Container/Definition/Definition.php(212): WP_Rocket\Dependencies\League\Container\Definition\Definition-&gt;resolveClass('WP_Rocket\\Engin...')
#3 /home/merc in <b>/home/merciket/public_html/wp-content/plugins/wp-rocket/inc/Engine/Optimization/RUCSS/Admin/Subscriber.php</b> on line <b>49</b><br />