connector/src/main/java/org/jboss/as/connector/util/ConnectorServices.java
public static <T> T notNull(T value) {
        if (value == null)
            throw ConnectorLogger.ROOT_LOGGER.serviceNotStarted();
        return value;
    }
public static <T> T notNull(T value) {
        if (value == null)
            throw ConnectorLogger.ROOT_LOGGER.serviceNotStarted();
        return value;
    }
convenient method to check notNull of value

@param <T> type of the value
@param value the value
@return the value or throw an {@link IllegalStateException} if value is null (a.k.a. service not started)