@Test
public void swapReplacesCurrentObjectWithMethodParameter() {

  Whitebox.setInternalState(testSubject, "currentObject", mockOldObject);
  GenericTestObject actualOldObject = testSubject.swap(mockIntermediateObject);
  GenericTestObject actualIntermediateObject = testSubject.swap(mockNewObject);
  Assert.assertEquals(mockOldObject, actualOldObject);
  Assert.assertEquals(mockIntermediateObject, actualIntermediateObject);
}