static void assertValidArgument(final boolean valid, final String message,
      final Object... arguments) {
    if (!valid) {
      throw new IllegalArgumentException(String.format(message, arguments));
    }
  }
Map used to register SignalListeners with SignalHandlers...
geode-core/src/main/java/org/apache/geode/internal/process/signal/AbstractSignalNotificationHandler.java