public void actionPerformed(final ActionEvent e) {
final ASelectableCondition[] selectedValues = toConditionsArray(elementaryConditionList.getSelectedValues());
if (selectedValues.length < 2) {
return;
}
final ASelectableCondition newCond = new DisjunctConditions(selectedValues);
final DefaultComboBoxModel model = (DefaultComboBoxModel) elementaryConditionList.getModel();
model.addElement(newCond);
validate();
}