How obtain the time taken for the method to be executed TESTNG

How obtain the time taken for the method to be executed TESTNG

How obtain the time taken for the method to be executed TESTNG?
for example
@Test(threadPoolSize = 100, invocationCount = 100)
public void testA() throws Exception {
System.out.println("hello");
}
It will run 100 times,now I want to obtain the time taken for the method
testA for every times
Thanks Nick