SonarCloud complains:
  The return value of "trim" must be used.

        // Try to get the custom text. If none, use the fallback
        String getApproveButtonText(final JFileChooser fc, final String fallbackText) {
            final String buttonText = fc.getApproveButtonText();
            if (buttonText != null) {
                buttonText.trim(); // <--- here
                if (!buttonText.isEmpty()) return buttonText;
            }
            return fallbackText;
        }

        String getApproveButtonToolTipText(final JFileChooser fc, final String fallbackText) {
            final String tooltipText = fc.getApproveButtonToolTipText();
            if (tooltipText != null) {
                tooltipText.trim(); // <--- here
                if (!tooltipText.isEmpty()) return tooltipText;
            }
            return fallbackText;
        }