@Test
    public void testCustomFieldMapper() {
        CustomFieldMapper customFieldMapper = new TestCustomFieldMapper();
        mapper = DozerBeanMapperBuilder.create()
                .withCustomFieldMapper(customFieldMapper)
                .build();

        String currentTime = String.valueOf(System.currentTimeMillis());
        SimpleObj src = newInstance(SimpleObj.class);
        src.setField1(currentTime);
        src.setField6("field6Value" + currentTime);

        SimpleObjPrime dest = mapper.map(src, SimpleObjPrime.class);

        assertNotNull("dest field1 should not be null", dest.getField1());
        assertNotNull("dest field6 should not be null", dest.getField6());
        assertEquals("dest field1 should have been set by custom field mapper", TestCustomFieldMapper.fieldValue, dest.getField1());
        assertEquals("dest field6 should NOT have been set by custom field mapper", src.getField6(), dest.getField6());
    }
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