what is the output of the following program?

public class sookshmas1{
   public static void main(string args[]){
      test(null);
   }
   public static void test(Object o){
      System.out.println("object");
   }
   public static void test(String s){
      System.out.println("string");
   }
   public static void test(Integer i){
      System.out.println("integer");
   } 
}