### Question:
AttributeHolderScope implements Scope, Provider<AHT> { public void exit() throws OutOfScopeException { assertInScope(); this.holder.get().pop(); }  void enter(final AHT holder); void exit(); @Override AHT get(); @Override final Provider<T> scope(
            final Key<T> key, final Provider<T> outer);  }### Answer:
@Test(expectedExceptions = OutOfScopeException.class) public void cannotExitWhenNotInScope() { scope.exit(); }