FluidTYPO3\Flux\Utility\CompatibilityRegistry::cache PHP Method

    protected static function cache(array &$source, $prefix, $scope, $version)
    {
        $key = $prefix . '-' . $scope . '-' . $version;
        if (TRUE === array_key_exists($key, static::$cache)) {
            return static::$cache[$key];
        } elseif (is_array($source[$scope])) {
            $value = static::resolveVersionedValue($source[$scope], $version);
            static::$cache[$key] = $value;
            return $value;
        } else {
            GeneralUtility::sysLog(sprintf('Possible misconfiguration or stale cached configuration: versioned attributes named "%s" requested from %s ' . 'but no such named attributes are registered. If flushing the system cache does not remove this message please ' . 'check your source code for possible typos in registration or usages of "%s".', $scope, static::class, $scope), GeneralUtility::SYSLOG_SEVERITY_WARNING);
        }
        return NULL;
    }