FileFilter popFilter = new FileNameEndingFilter(
"SUMO population files (.pop or .pop.xml)", ".pop", ".pop.xml");
dialog.addChoosableFileFilter(popFilter);
dialog.setFileFilter(popFilter);
if (dialog.showDialog(parentWindow, "Export") == JFileChooser.APPROVE_OPTION) {
new SumoPopulationExport(dialog.getSelectedFile()).start();
}
}