private CharSequence appendAccessModifier(ExecutableElement m, StringBuilder signature) {
    if (m.getModifiers().contains(Modifier.PUBLIC)) {
      return signature.append("public ");
    }
    if (m.getModifiers().contains(Modifier.PROTECTED)) {
      return signature.append("protected ");
    }
    return signature;
  }
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