Java etc.

public class TestSuite1 {
   public static Test suit() {
      TestSuite testSuite = new TestSuite();
      testSuite.addTestSuite(Test1.class);
      testSuite.addTestSuite(Test2.class);
      return testSuite;
   }
}
public class TestSuiteOfTestSuites {
   public static Test suit() {
      TestSuite testSuite = new TestSuite();
      testSuite.addTest(TestSuite1.suite());
      return testSuite;
   }
}