### Question:
ModelBasedArgumentConverter implements ArgumentConverter { public void initialize(ModelConverter modelConverter) { this.modelConverter = Preconditions.notNull(modelConverter); }  void initialize(ModelConverter modelConverter);  }### Answer:
@Test void converterCannotBeNull() { assertThrows(NullPointerException.class, () -> CONVERTER.initialize(null)); }
@Test void initializationWorksCorrectly() { final ModelConverter converter = Mockito.mock(ModelConverter.class); CONVERTER.initialize(converter); assertEquals(converter, CONVERTER.modelConverter); }