code: function identifier(proto, attrName) {
      var metadataManager = Vessel$$1.$container.get('@metadata_manager'), className = proto.getClassName();
      metadataManager.setIdentifier(className, attrName);
  }
docs: Decorator: @attr
  
  Adds the name of the identifier attribute to
  the metadata manager.
  
  This will be used by the framework so it knows what
  are the model identifier.
  
  @param proto
  @param attrName