private static bool LoadSettings()
        {
            // インスタンスを経由して自身のファイルパスを取得
            // Retrieve its own file path via instance.
            var    window = GetWindow <ReferenceViewerMenu>();
            string path   = window.GetSettingFilePath();

            window.Close();

            settings = AssetDatabase.LoadAssetAtPath <ExcludeSettings>(path);
            if (settings == null)
            {
                UnityEngine.Debug.LogError("[ReferenceViewer] Failed to load exclude setting file.");
                return(false);
            }
            return(true);
        }