private String[] getResult(final Argument arg) {
    final List<String[]> all = getAllResults(arg);
    if (all == null) {
      return null;
    } else {
      return all.get(0);
    }
  }
Convenience method to retrieve the first instance of the command line argument's values.

@param arg argument to query
@return first parameter list defined for this argument
extensions/geode-modules-session/src/main/java/org/apache/geode/modules/session/installer/args/ArgumentValues.java