protected String get(Map<String, List<String>> data, String key, int value) {
        List<String> list = data.get(key);
        if (list == null) {
            return null;
        } else {
            return list.get(value);
        }
    }
Adds the allowed actions to follow from the current stage. Possible actions are:
{@code prev}, {@code next} and {@code complete}.

@param data metadata and the gathered data through the command stages.
@param command the command element to be sent to the command requester.
xmppserver/src/main/java/org/jivesoftware/openfire/commands/AdHocCommand.java