public function load(string $pathAndFilename, bool $allowSplitSource = false): array
    {
        $this->detectFilesWithWrongExtension($pathAndFilename, $allowSplitSource);
        $pathsAndFileNames = [$pathAndFilename . '.yaml'];
        if ($allowSplitSource === true) {
            $splitSourcePathsAndFileNames = glob($pathAndFilename . '.*.yaml');
            $splitSourcePathsAndFileNames = array_merge($splitSourcePathsAndFileNames, glob($pathAndFilename . '.*.yml'));
            if ($splitSourcePathsAndFileNames !== false) {
                sort($splitSourcePathsAndFileNames);
                $pathsAndFileNames = array_merge($pathsAndFileNames, $splitSourcePathsAndFileNames);
            }
        }
        $configuration = [];
        foreach ($pathsAndFileNames as $pathAndFilename) {
            $configuration = $this->mergeFileContent($pathAndFilename, $configuration);
        }
        return $configuration;
    }