public List<ValueAttribute> getExcludableAttributes() {
    List<ValueAttribute> excludables = Lists.newArrayList();
    for (ValueAttribute attribute : attributes()) {
      if (attribute.isGenerateAbstract && (attribute.isContainerType() && !attribute.isArrayType())) {
        excludables.add(attribute);
      }
    }
    return excludables;
  }
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