@Test
public void shouldNotAddBsonConfWithCustomMapper() throws Exception {
Mapping.Builder builder = new Mapping.Builder(new ObjectMapper());
Mapping mapping = builder.build();
ObjectId id = ObjectId.get();//serialized using bson serializer
Friend friend = new Friend(id, "John");
Writer writer = new StringWriter();
mapping.getWriter(friend).writeValue(writer, friend);
assertThat(writer.toString()).contains("John");