title: #<FastJsonapi::MandatoryField: id is a mandatory field in the jsonapi spec>
body: <p>When trying to pass an enum object to serializer I get the following error:</p>
  
  <p><code>#&lt;FastJsonapi::MandatoryField: id is a mandatory field in the jsonapi spec&gt;</code></p>
  
  <p><code>@drop_down_values = Organisation.ownerships</code>
  where @drop_down_values has the enum values from ownership column.</p>
  
  <p><code>render json: DropDownValueSerializer.new(@drop_down_values).serialized_json</code></p>