retrofit/src/main/java/retrofit2/Retrofit.java
public <T> Converter<ResponseBody, T> responseBodyConverter(Type type, Annotation[] annotations) {
    return nextResponseBodyConverter(null, type, annotations);
  }
public <T> Converter<ResponseBody, T> responseBodyConverter(Type type, Annotation[] annotations) {
    return nextResponseBodyConverter(null, type, annotations);
  }
Returns a {@link Converter} for {@link ResponseBody} to {@code type} from the available
{@linkplain #converterFactories() factories}.

@throws IllegalArgumentException if no converter available for {@code type}.