private void appendHeader(@NotNull Writer writer, String title) throws IOException {
    writer.append("""
                    <html>
                    <head>
                      <meta http-equiv="Content-Type" content="text/html;charset=utf-8">
                      <meta name="author" content="JetBrains">
                      <script type="text/javascript" src="script.js"></script>
                      <link rel="stylesheet" type="text/css" href="styles.css">
                      <title>""")
      .append(title)
      .append("""
                  </title>
                </head>
                <body>
                """);
  }
private void appendHeader(@NotNull Writer writer, String title)