Illustrates use of Groovy traits to safely start a thread through the run() method instead of the proper start() method

SafeThreadStarter

trait SafeStarter {
    private boolean started = false
    public void run() {
        if (!started) {
          this.start()
          started = true
        }
        super.run()
    }
}

println "Main thread: ${Thread.currentThread()}"
def t = new Thread({println "Running in ${Thread.currentThread()}"}).withTraits SafeStarter
t.run()  //This is normally a mistake, start() should be called on a thread to start running asynchronously