诡异的写法

public class MultiThreadTest {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		debug d = new MultiThreadTest.debug("Hello");
		d.log();
	}

	static public class debug extends RuntimeException{
		public void log(){
			System.out.println("Hello World");
		}
		public debug(String obj){
			super(obj);
		}
	}
}