// same freshness, generate again.
          return invokeGeneratorMethod(emptyGenerate);
        } else {
          // Cannot use empty generator. Proceed with other generators.
        }
      } else {
        // never generated empty instance for this type before.
        Object emptyInstance = invokeGeneratorMethod(emptyGenerate);
        emptyInstanceGenerated.put(type.getType(), freshness.get());

          // same freshness, generate again.
          return invokeGeneratorMethod(emptyGenerate);
        } else {
          // Cannot use empty generator. Proceed with other generators.
        }
      } else {
        // never generated empty instance for this type before.
        Object emptyInstance = invokeGeneratorMethod(emptyGenerate);
        emptyInstanceGenerated.put(type.getType(), freshness.get());