TestNG IMethodInterceptor两次拦截测试类

Question

我有一个简单的测试用例

@Listeners(MyListener.class)
public class SampleTestCase {

@Test
public void testCase1() {
    Assert.assertTrue(true, "Let it pass all the time");
}
}

听众的位置

public class MyListener implements IMethodInterceptor {

static int count = 1;

@Override
public List<IMethodInstance> intercept(List<IMethodInstance> methods, ITestContext context) {
    System.out.println("Intercepted " + count++);
    return methods;
}
}

输出是：

截获1

截获2

PASSED：testCase1

为什么要截获两次？