code: private void buttonExtensionsOpenInSystemActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_buttonExtensionsOpenInSystemActionPerformed
      final SysFileExtensionEditorPanel dataPanel = new SysFileExtensionEditorPanel(SystemFileExtensionManager.getInstance().getExtensionsAsCommaSeparatedString());
      if (DialogProviderManager.getInstance().getDialogProvider().msgOkCancel(this, "System file extensions", dataPanel)) {
        SystemFileExtensionManager.getInstance().setExtensionsAsCommaSeparatedString(dataPanel.getValuerNullIfDefault());
      }
    }
docs: GEN-LAST:event_buttonGraphvizDotFileActionPerformed