Document how defaults for entity properties should be provided

class EntityAffiliateCampaign extends Entity {
  public function __construct(array $values = array(), $entityType = NULL) {
    // Add default values, if they are not set.
    $values += array(
      'name' => '',
      'affiliate_uid' => 0,
      'is_default' => FALSE,
    );
    parent::__construct($values, 'affiliate_campaign');
  }
}

That's my entity class. It initializes some important values so that I don't get an empty object from entity_create().
However, this gives me a problem with entity_load, because the entity controller does this:

$result->setFetchMode(PDO::FETCH_CLASS, $this->entityInfo['entity class'], array(array(), $this->entityType));

What this line of code does is prefill an object from the database values, THEN calls it's constructor.
And the default entity class constructor does this:

// Set initial values.
    foreach ($values as $key => $value) {
      $this->$key = $value;
    }

Thus overwriting the already set values, and giving me an empty object.

Attaching a sensible patch.
This could also be a support request if you think I'm doing the whole defaults thing wrong :P