@GwtCompatible
@NullUnmarked
public class ConverterTest extends TestCase {

  private static final Converter<String, Long> STR_TO_LONG =
      new Converter<String, Long>() {
        @Override
        protected Long doForward(String object) {
          return Long.valueOf(object);
        }

        @Override
        protected String doBackward(Long object) {
          return String.valueOf(object);
        }

        @Override

      implements Serializable {

    private final Class<T> enumClass;

    StringConverter(Class<T> enumClass) {
      this.enumClass = checkNotNull(enumClass);
    }

    @Override
    protected T doForward(String value) {
      return Enum.valueOf(enumClass, value);
    }

    @Override
    protected String doBackward(T enumValue) {
      return enumValue.name();
    }

    @Override

      this.sourceFormat = checkNotNull(sourceFormat);
      this.targetFormat = checkNotNull(targetFormat);
    }

    @Override
    protected String doForward(String s) {
      return sourceFormat.to(targetFormat, s);
    }

    @Override
    protected String doBackward(String s) {
      return targetFormat.to(sourceFormat, s);
    }

    @Override

      this.sourceFormat = checkNotNull(sourceFormat);
      this.targetFormat = checkNotNull(targetFormat);
    }

    @Override
    protected String doForward(String s) {
      return sourceFormat.to(targetFormat, s);
    }

    @Override
    protected String doBackward(String s) {
      return targetFormat.to(sourceFormat, s);
    }

    @Override