@Test
    public void testNullField() {
        mapper = getMapper("mappings/testDozerBeanMapping.xml");
        AnotherTestObject src = newInstance(AnotherTestObject.class);
        src.setField2(null);
        AnotherTestObjectPrime dest = newInstance(AnotherTestObjectPrime.class);
        dest.setField2(Integer.valueOf("555"));
        // check that null overrides an existing value
        mapper.map(src, dest);
        assertNull("dest field should be null", dest.getField2());
    }
When the source type is a Set and the destination is a Collection we expect that the
mapper narrows to the Set type instead of using a List by default.
<p>
issue https://github.com/DozerMapper/dozer/issues/287
core/src/test/java/com/github/dozermapper/core/functional_tests/GranularDozerBeanMapperTest.java