class ActiveFedora::Associations::Builder::CollectionAssociation

def self.define_callback(model, callback_name, name, options)
  full_callback_name = "#{callback_name}_for_#{name}"
  # TODO : why do i need method_defined? I think its because of the inheritance chain
  model.class_attribute full_callback_name.to_sym unless model.method_defined?(full_callback_name)
  model.send("#{full_callback_name}=", Array(options[callback_name.to_sym]))
end