package kata.lib;

public class HelloLib implements HelloLibIF{
    public void doSomething() {
        System.out.println("Hello Library - Java 7!");
        System.out.println(String.format("The library is running under Java version %s", System.getProperty("java.version")));

        System.out.println("The stack is:");
        for(StackTraceElement element : Thread.currentThread().getStackTrace()) {
            System.out.println(element);
        }
    }
}

Create HelloLib.java