Using `contains` for metadata

codex.rb

class Codex < ActiveFedora::Base
  contains 'descMetadata', class_name: 'CodexMetadata'

  property :title, delegate_to: 'descMetadata', multiple: false
  property :author, delegate_to: 'descMetadata', multiple: false

end

rails-console.output

$ rails c
Running via Spring preloader in process 14384
Loading development environment (Rails 4.2.6)
2.3.0 :001 > c=Codex.new(id: 'test-2')
NoMethodError: undefined method `contains' for Codex:Class
Did you mean?  constants
	from /vagrant/hydra-demo/app/models/codex.rb:2:in `<class:Codex>'
	from /vagrant/hydra-demo/app/models/codex.rb:1:in `<top (required)>'
	from /home/vagrant/.rvm/gems/ruby-2.3.0/gems/activesupport-4.2.6/lib/active_support/dependencies.rb:457:in `load'
	from /home/vagrant/.rvm/gems/ruby-2.3.0/gems/activesupport-4.2.6/lib/active_support/dependencies.rb:457:in `block in load_file'
	from /home/vagrant/.rvm/gems/ruby-2.3.0/gems/activesupport-4.2.6/lib/active_support/dependencies.rb:647:in `new_constants_in'
	from /home/vagrant/.rvm/gems/ruby-2.3.0/gems/activesupport-4.2.6/lib/active_support/dependencies.rb:456:in `load_file'
	from /home/vagrant/.rvm/gems/ruby-2.3.0/gems/activesupport-4.2.6/lib/active_support/dependencies.rb:354:in `require_or_load'
	from /home/vagrant/.rvm/gems/ruby-2.3.0/gems/activesupport-4.2.6/lib/active_support/dependencies.rb:494:in `load_missing_constant'
	from /home/vagrant/.rvm/gems/ruby-2.3.0/gems/activesupport-4.2.6/lib/active_support/dependencies.rb:184:in `const_missing'
	from (irb):1
	from /home/vagrant/.rvm/gems/ruby-2.3.0/gems/railties-4.2.6/lib/rails/commands/console.rb:110:in `start'
	from /home/vagrant/.rvm/gems/ruby-2.3.0/gems/railties-4.2.6/lib/rails/commands/console.rb:9:in `start'
	from /home/vagrant/.rvm/gems/ruby-2.3.0/gems/railties-4.2.6/lib/rails/commands/commands_tasks.rb:68:in `console'
	from /home/vagrant/.rvm/gems/ruby-2.3.0/gems/railties-4.2.6/lib/rails/commands/commands_tasks.rb:39:in `run_command!'
	from /home/vagrant/.rvm/gems/ruby-2.3.0/gems/railties-4.2.6/lib/rails/commands.rb:17:in `<top (required)>'
	from /home/vagrant/.rvm/gems/ruby-2.3.0/gems/activesupport-4.2.6/lib/active_support/dependencies.rb:274:in `require'
	from /home/vagrant/.rvm/gems/ruby-2.3.0/gems/activesupport-4.2.6/lib/active_support/dependencies.rb:274:in `block in require'
	from /home/vagrant/.rvm/gems/ruby-2.3.0/gems/activesupport-4.2.6/lib/active_support/dependencies.rb:240:in `load_dependency'
	from /home/vagrant/.rvm/gems/ruby-2.3.0/gems/activesupport-4.2.6/lib/active_support/dependencies.rb:274:in `require'
	from /vagrant/hydra-demo/bin/rails:9:in `<top (required)>'
	from /home/vagrant/.rvm/gems/ruby-2.3.0/gems/activesupport-4.2.6/lib/active_support/dependencies.rb:268:in `load'
	from /home/vagrant/.rvm/gems/ruby-2.3.0/gems/activesupport-4.2.6/lib/active_support/dependencies.rb:268:in `block in load'
	from /home/vagrant/.rvm/gems/ruby-2.3.0/gems/activesupport-4.2.6/lib/active_support/dependencies.rb:240:in `load_dependency'
	from /home/vagrant/.rvm/gems/ruby-2.3.0/gems/activesupport-4.2.6/lib/active_support/dependencies.rb:268:in `load'
	from /home/vagrant/.rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
	from /home/vagrant/.rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
	from -e:1:in `<main>'2.3.0 :002 > 

Any solution to this?

class Codex < ActiveFedora::Base
directly_contains :descMetadata, has_member_relation: ::RDF::URI.new("http://example.com/hasFiles"), class_name: :CodexMetadata

property :title, predicate: ::RDF::Vocab::DC.title, multiple: false, delegate_to: :descMetadata
property :author, predicate: ::RDF::Vocab::DC.creator, multiple: false, delegate_to: :descMetadata
end

This works, I think, am new to the whole hydra thing.

Note for others... see samvera-deprecated/hydra#112