@Test
public void appendImports_emptyCollection_after_filtering_prints_nothing() throws Exception {

  FileContextTestImpl fileContext = new FileContextTestImpl();
  new DAFileWriter(fileContext.getWriter()).appendImports(
      ImmutableList.of(DAImportImpl.from(DANameFactory.from(String.class.getName())))
  );
  assertThat(fileContext.getRes()).isEqualTo("");
}