private boolean isOutsideFStringOrInsideItsLineBreakSensitiveTextPart() {
    if (myFStringStack.isEmpty()) return true;
    FString topmostFString = myFStringStack.peek();
    // In triple-quoted f-strings one can put line breaks in any plain-text part
    if (topmostFString.quotes.length() != 1) return false;
    return topmostFString.fragments.isEmpty() || topmostFString.fragments.peek() == FStringFragmentPart.TYPE_CONVERSION_OR_FORMAT;
  }
private boolean isOutsideFStringOrInsideItsLineBreakSensitiveTextPart()