private void addSubsetAcessory() {
subsetButton = new JButton("Subset...");
subsetButton.setMnemonic('S');
subsetButton.addActionListener(e -> openProductSubsetDialog());
subsetButton.setEnabled(getSelectedFile() != null || productToExport != null);
sizeLabel = new JLabel("0 M");
sizeLabel.setHorizontalAlignment(JLabel.RIGHT);
JPanel panel = GridBagUtils.createPanel();
GridBagConstraints gbc = GridBagUtils.createConstraints(
"fill=HORIZONTAL,weightx=1,anchor=NORTHWEST,insets.left=7,insets.right=7,insets.bottom=4");
GridBagUtils.addToPanel(panel, subsetButton, gbc, "gridy=0");
GridBagUtils.addToPanel(panel, sizeLabel, gbc, "gridy=1");
GridBagUtils.addVerticalFiller(panel, gbc);
setAccessory(panel);
addPropertyChangeListener(e -> updateState());
}