void (final Collection<ProxyGroup> newUserGroups) { final Map<String, ProxyGroup> oldGroups = getGroups(); for (ProxyGroup proxyGroup : newUserGroups) { if (proxyGroup.isDefault()) { processGroup(proxyGroup, getDefaultGroup(), false); } else { findAndProcessGroup(proxyGroup, oldGroups); } } for (String groupName : oldGroups.keySet()) { myFile.deleteGroup(groupName); } myFile.save(); }