### Question:
CommandBuilder { static String buildReturnClasses(String returnType) { return "{" + buildReturnClassesRecursive(returnType) + "}"; } CommandBuilder(
      String basePackageName,
      JavaBuilderFactory javaBuilderFactory,
      String typesPackageName,
      String eventPackageName,
      String supportTypesPackageName); Builder build(Domain domain, DomainTypeResolver domainTypeResolver);  }### Answer:
@Test public void testBuildReturnClasses() { assertEquals("{Test.class}", buildReturnClasses("Test")); assertEquals("{List.class,Test.class}", buildReturnClasses("List<Test>")); assertEquals("{List.class,List.class,Test.class}", buildReturnClasses("List<List<Test>>")); }