Call a block of a method only for the first call of the method

Question

I have a method and inside this method I have a block:

public void method()
{
   [block instructions]
}

But this method is called twice in

Answer 1

private static final AtomicBoolean hasRunAtom = new AtomicBoolean();

public void method() {
  if (hasRunAtom.getAndSet(true)) return;
  [block instructions]
}