public boolean isGenerateBuilderUseCopyConstructor() {
    return isUseBuilder()
        && isUseCopyMethods()
        && allAttributesSupportsThis()
        && !isOrdinalValue()
        && getDefaultAttributes().isEmpty();
  }
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