TestNG - How to call individual Test classes in MultipleTest Class

I am starting to use selenium webdriver with TestNG. I have created a multiple-test class which can run multiple tests, however, how do I call the other classes in each test block without copying the whole code over?

 public WebDriver driver;
  //Test 1
  @Test(priority = 0) //Set Priority of Test - Priority of test always starts from Zero
 public void one() {

  System.out.println("This is Test Case 1");
  }
//Test 2
 @Test(priority = 1) // Test priority 1
 public void Two(){

  System.out.println("This is Test Case 2");
  }

Would I need to create a function to call in each test block to run the other classes?