Assert that a method was called with an object that is changed in the method

Thats the method I want to test:

public void Set1(ViewModelA viewModelA)
{
   var viewModelB = new ViewModelB
   {
      FirstName = viewModelA.FirstName,
      LastName = viewModelB.LastName
   }
   service.Set2(viewModelB);
}

How can I assert that the viewModelB instance passed to service.Set2 has the property values mapped from viewModelA and that Set2 took viewModelB as parameter?