public function loadFile($path)
    {
        if (!is_string($path)) {
            throw new InvalidArgumentException(
                'File must be a string'
            );
        }

        if (!file_exists($path)) {
            throw new InvalidArgumentException(
                sprintf('File "%s" does not exist', $path)
            );
        }

        $ext = pathinfo($path, PATHINFO_EXTENSION);
        switch ($ext) {
            case 'php':
                return $this->loadPhpFile($path);

            case 'json':
                return $this->loadJsonFile($path);

            case 'ini':
                return $this->loadIniFile($path);

            case 'yml':
            case 'yaml':
                return $this->loadYamlFile($path);
        }

        $validConfigExts = [ 'ini', 'json', 'php', 'yml' ];
        throw new InvalidArgumentException(sprintf(
            'Unsupported file format for "%s"; must be one of "%s"',
            $path,
            implode('", "', $validConfigExts)
        ));
    }