PowerMock mock creation of new object of generic class

I need to mock creation of two objects

Holder<MyClass1> h1 = new Holder<>();
Holder<MyClass2> h2 = new Holder<>();

I use Mockito and PowerMock

Holder<MyClass1> mock1 = PowerMockito.spy(new Holder<MyClass1>());
Holder<MyClass2> mock2 = PowerMockito.spy(new Holder<MyClass2>());

PowerMockito.whenNew(Holder.class).withNoArguments().thenReturn(mock1);

How can I specify generic type to mock two different objects? I need 2 mock for my test. Thank you.