This week's book giveaways are in the iOS and Features new in Java 8 forums. We're giving away four copies each of Barcodes with iOS: Bringing together the digital and physical worlds and Core Java for the Impatient and have the authors on-line! See this thread and this one for details.
because the compiler knows that an instance of a Ticker cannot possibly be a string - it can see that String extends Object and Ticker extends Component which itself extends Object. so a Ticker can not be an instance of String.