e https://stackoverflow.com/a/52641198/2883487
     */
    public static function deepFixMixedUTF8Encoding($data) {
        if (is_array($data)) {
            foreach ($data as $key => $value) {
                $data[$key] = static::deepFixMixedUTF8Encoding($value);
            }

        } else if (is_string($data)) {
            return mb_convert_encoding($data, "UTF-8", "UTF-8");
        }

        return $data;
    }

    /**
     * Get current locale's code. The language code's part that comes before underscore '_' char is returned.
     *
     * @return string Language code of the current locale of WP
     * @since 1.8.0
     */
    public static function getLocaleCode() {
        // Get the locale from WP
        $locale = get_locale();

        // If there exists a locale and it contains an underscore
        if ($locale && Str::contains($locale, '_')) {
            // Get the part coming before the underscore
            $exploded = explode('_', $locale);
            $locale = $exploded[0];

        // Otherwise, if there is no locale, set a default code.
        } else if (!$locale) {
            $locale = 'en';
        }

        return $locale;
    }

    /**
     * Get published sites.
     *
     * @return array See {@link get_posts}.
     * @uses get_posts
     * @since 1.9.0
     */
    public static function getSites() {
        // If the value was prepared before, return it.
        if (static::$SITES) return static::$SITES;

        // Get the sites
        $sites = get_posts(['post_type' => Environment::postType(), 'numberposts' => -1]);

        // Define a default title for the sites that do not have a title.
        $defaultTitle = _wpcc('(no title)');

        // Prepare the sites
        array_walk($sites, function($item) use (&$defaultTitle) {
            /** @var WP_Post $item */

            // If the site does not have a title, set its title as the default title.
            if (!$item->post_title) $item->post_title = $defaultTitle;

            // Add the ID to the title.
            $item->post_title .= " ({$item->ID})";
        });

        static::$SITES = $sites;

        return static::$SITES;
    }

    /**
     * @return array See {@link Utils::$authors}
     * @since 1.11.0
     */
    public static function getAuthors() {
        if (static::$authors === null) {
            // Get authors
            $authorsRaw = get_users([
                'orderby'   =>  'nicename',
                'fields'    =>  ['ID', 'user_nicename']
            ]);

            static::$authors = [];
            foreach($authorsRaw as $author) {
                static::$authors[$author->ID] = $author->user_nicename;
            }
        }

        return static::$authors;
    }

    /**
     * Get post statuses
     *
     * @return array<int|string, string> An associative array of post statuses where keys are unique status keys and
     * values are human-readable names.
     *
     * @since 1.11.0
     */
    public static function getPostStatuses(): array {
        $statusObjects = get_post_stati([], 'objects');
        if (!$statusObjects) return [];

        $result = [];
        foreach($statusObjects as $statusObject) {
            $name  = $statusObject->name  ?? null;
            $label = $statusObject->label ?? _wpcc('Unknown');
            if ($name === null) continue;

            $result[$name] = "$label ($name)";
        }

        return $result;
    }

    /**
     * Get sites in a structure that can be used to easily show them in a select element.
     *
     * @return array A key-value pair where the keys are site IDs and the values are the site names.
     * @uses Utils::getSites()
     * @since 1.9.0
     */
    public static function getSitesForSelect() {
        // Get available sites
        $availableSites = Utils::getSites();
        if (!$availableSites) return [];

        $sites = [];
        foreach($availableSites as $site) {
            $sites[$site->ID] = $site->post_title;
        }

        return $sites;
    }

    /**
     * Remove empty strings from a sequential array
     *
     * @param array $arr A sequential array
     * @return array Filtered sequential array
     * @since 1.9.0
     */
    public static function filterEmptyStrings($arr) {
        return array_filter($arr, function($v) {
            return $v !== '';
        });
    }

    /**
     * Check if an option is selected or not.
     *
     * @param string       $optionValue
     * @param array|string $selectedValues
     * @return bool True if the option is selected.
     * @since 1.9.0
     */
    public static function isOptionSelected($optionValue, $selectedValues) {
        return !is_array($selectedValues) ?
            $selectedValues == $optionValue :
            array_search($optionValue, $selectedValues) !== false;
    }

    /**
     * Prepare a query string with the given parameters. This method creates the query string considering the given URL.
     *
     * @param string $url    URL for which the query string should be prepared
     * @param array  $params Query parameters
     * @return string Query string starting with either "&" or "?" depending on the given URL.
     * @since 1.9.0
     */
    public static function buildQueryString($url, $params) {
        if (!$params) return $url;
        return (Str::contains($url, '?') ? '&' : '?') . http_build_query($params);
    }

    /**
     * Escapes special characters in the regular expression replacement strings
     *
     * @param string $replacementStr
     * @return mixed
     * @since 1.9.0
     */
    public static function quoteRegexReplacementString(string $replacementStr) {
        return str_replace('$', '\\$', $replacementStr);
    }

    /**
     * @return bool True if the script is called from an AJAX request.
     * @since 1.9.0
     */
    public static function isAjax() {
        return defined('DOING_AJAX') && DOING_AJAX;
    }

    /**
     * @return bool True if the current page belongs to the plugin. Otherwise, false.
     * @since 1.9.0
     */
    public static function isPluginPage() {
        global $post_type;
        if ($post_type && strtolower($post_type) === strtolower(Environment::postType())) return true;

        if(!isset($_GET)) return false; // @phpstan-ignore-line
        return isset($_GET['post_type']) && strtolower($_GET['post_type']) === strtolower(Environment::postType());
    }

    /**
     * Get the items existing in all of the arrays
     *
     * @param mixed ...$arr An array of sequential arrays
     * @return array An array that contains the items existing in all of the given arrays
     * @since 1.11.0
     */
    public static function arrayIntersect(...$arr): array {
        if (!$arr || sizeof($arr) < 2) return [];

        $smallestIndex = 0;
        $smallest = $arr[$smallestIndex];

        // If the smallest array is an empty array, the intersection is an empty array.
        if (!$smallest) return [];

        // Find the smallest-size array
        $smallestSize = sizeof($smallest);
        for($i = 1; $i < sizeof($arr); $i++) {
            // If an array is empty, the intersection is an empty array.
            if (!$arr[$i]) return [];

            if (sizeof($arr[$i]) >= $smallestSize) continue;

            $smallest = $arr[$i];
            $smallestSize = sizeof($smallest);
            $smallestIndex = $i;
        }

        // Remove the smallest-size array from the given arrays
        unset($arr[$smallestIndex]);

        // Items in the smallest-size array must exist in all other arrays.
        foreach($arr as $item) {
            if (!$smallest) return []; // @phpstan-ignore-line

            foreach($smallest as $k => $target) {
                // If the item exists, continue with the next one.
                if (in_array($target, $item, true)) continue;

                // This item does not exist in the smallest-size array. Remove it.
                unset($smallest[$k]);
                if (!$smallest) return []; // @phpstan-ignore-line
            }
        }

        // The smallest-size array is the intersection array.
        return $smallest;
    }

    /**
     * @param object[]|null $arr A sequential object array whose unique items are needed
     * @return object[] An array of unique objects
     * @since 1.11.0
     */
    public static function arrayUniqueObject(?array $arr): array {
        if ($arr === null || !$arr) return [];

        $idArray = [];
        foreach($arr as $item) {
            if (!is_object($item)) continue;

            // spl_object_id is a unique ID given to each object. So, the ID array can only have unique objects since
            // unique IDs are used as keys. If an object has the same ID as an object existing in the ID array, then
            // it will just be reassigned. So, ID array is unique.
            $idArray[spl_object_id($item)] = $item;
        }

        // Just return the values of the ID array as the final unique array.
        return array_values($idArray);
    }

    /**
     * Check if a plugin is currently active. This method is created by examining {@link is_plugin_active()} and
     * {@link is_plugin_active_for_network()}. These functions are available in "admin_init" event, while this method
     * is available any time.
     *
     * @param string|null $plugin Path of the plugin's entrypoint file relative to the "plugins" directory. For
     *                            example, for WooCommerce, this is "woocommerce/woocommerce.php".
     * @return bool
     * @since 1.11.0
     */
    public static function isPluginActive(?string $plugin): bool {
        if (!$plugin) return false;

        // If this is not a multi site
        if (!is_multisite()) {
            return in_array($plugin, apply_filters('active_plugins', get_option('active_plugins')));
        }

        // This is a multi site installation. Get site-wide active plugins.
        $activePlugins = get_site_option('active_sitewide_plugins');

        // Make sure it is an array, since the return type does not guarantee that.
        return !is_array($activePlugins)
            ? false
            : in_array($plugin, array_keys($activePlugins));
    }

    /**
     * @return array|string[] Decimal separator options that can be shown in a select form item
     * @since 1.11.0
     */
    public static function getDecimalSeparatorOptionsForSelect(): array {
        return [
            'dot'   => _wpcc('Dot') . ' (.)',
            'comma' => _wpcc('Comma') . ' (,)',
        ];
    }

    /**
     * Check if an array has non-empty values. This does not check inner arrays.
     *
     * @param array $arr An array
     * @return bool True if the array has values that are non-empty
     * @since 1.11.0
     */
    public static function hasNonEmptyValues(array $arr): bool {
        return !empty(array_filter($arr, function($v) {
            if (is_array($v) || is_object($v)) {
                return !empty($v);
            }

            return $v !== '';
        }));
    }

    /**
     * Shifts the first key from a dot key. The dot key will be set to the remaining key after this operation. The first
     * key will be returned. The remaining key, i.e. the value of $dotKey, will be an empty string if the given $dotKey
     * has only one part.
     *
     * @param string|null $dotKey    A dot notation key
     * @param string      $separator The separator used in the dot key. This is typically '.'
     * @return string|null First key. If the dotKey is null or an empty string, returns null. If the dot key could not
     *                     be separated by using the given separator, returns null.
     * @since 1.11.1
     */
    public static function shiftFirstKey(?string &$dotKey, string $separator = '.'): ?string {
        if ($dotKey === null || $dotKey === '') {
            return null;
        }

        // Explode the dot key from the separators. Set the limit as 2 since we need the first key and the rest of the
        // dot key.
        $exploded = explode($separator, $dotKey, 2);
        if ($exploded) {
            // Get the first key
            $firstKey = $exploded[0];

            // The remaining dot key should be in the index 1.
            $dotKey = $exploded[1] ?? '';
            return $firstKey;
        }

        return null;
    }

    /**
     * Get the details of attachments with their IDs
     *
     * @param string[]|int[]|null $attachmentIds IDs of the attachments whose information is needed
     * @return array<int, array>|null An array whose keys are attachment IDs and whose values are the information about
     *                                the attachments retrieved via {@link wp_prepare_attachment_for_js()}.
     * @since 1.12.0
     */
    public static function getAttachmentInfo(?array $attachmentIds): ?array {
        if (!$attachmentIds) return null;

        $preparedIds = array_filter(array_map(function($value) {
            return is_numeric($value)
                ? (int) $value
                : null;
        }, $attachmentIds));

        // Get the attachments
        $attachments = get_posts([
            'numberposts' => -1,
            'orderby'     => 'post__in',
            'include'     => $preparedIds,
            'post_status' => 'any',
            'post_type'   => 'attachment',
        ]);

        // Prepare the attachment details
        $result = [];
        foreach($attachments as $attachment) {
            if (!($attachment instanceof WP_Post)) continue;

            $info = wp_prepare_attachment_for_js($attachment) ?: null;
            if (!is_array($info)) continue;

            $result[$attachment->ID] = $info;
        }

        return $result;
    }
}
<br />
<b>Fatal error</b>:  Uncaught Error: Class 'WPCCrawler\Utils' not found in /home/healths/public_html/wp-content/plugins/wp-content-crawler/app/RequirementValidator.php:58
Stack trace:
#0 /home/healths/public_html/wp-content/plugins/wp-content-crawler/app/WPCCrawler.php(58): WPCCrawler\RequirementValidator-&gt;validateAll()
#1 /home/healths/public_html/wp-content/plugins/wp-content-crawler/app/WPCCrawler.php(44): WPCCrawler\WPCCrawler-&gt;__construct()
#2 /home/healths/public_html/wp-content/plugins/wp-content-crawler/wp-content-crawler.php(28): WPCCrawler\WPCCrawler::getInstance()
#3 /home/healths/public_html/wp-settings.php(473): include_once('/home/healths/p...')
#4 /home/healths/public_html/wp-config.php(99): require_once('/home/healths/p...')
#5 /home/healths/public_html/wp-load.php(50): require_once('/home/healths/p...')
#6 /home/healths/public_html/wp-blog-header.php(13): require_once('/home/healths/p...')
#7 /home/healths/public_html/index.php(17): require('/home/healths/p...')
#8 {main}
  thrown in <b>/home/healths/public_html/wp-content/plugins/wp-content-crawler/app/RequirementValidator.php</b> on line <b>58</b><br />