private boolean hasSomeUnresolvedTypes() {
    for (ValueType n : nested) {
      for (ValueAttribute a : n.attributes) {
        if (a.hasSomeUnresolvedTypes) {
          return true;
        }
      }
    }
    for (ValueAttribute a : attributes) {
      if (a.hasSomeUnresolvedTypes) {
        return true;
      }
    }
    return false;
  }
Means object hashcode is cached at some point. Either lazily (on first access)
or eagerly (during construction).
@see #isUseLazyhash()
@see #isUsePrehashed()
value-processor/src/org/immutables/value/processor/meta/ValueType.java