@NotNull
  private static String formatErrorMessage(final String header, Throwable ex) {
    StringWriter stringWriter = new StringWriter();
    stringWriter.write(header);
    stringWriter.write(":\n");
    ex.printStackTrace(new PrintWriter(stringWriter));
    return stringWriter.getBuffer().toString();
  }
@NotNull
  private static String formatErrorMessage(final String header, Throwable ex)