https://crystaldoc.info/github/spider-gazelle/active-model/v4.3.3/ActiveModel/Model/Missing.html
ActiveModel::Model::Missing - active-model v4.3.3
activemodelmissing
https://rubygems.org/gems/rspec-activemodel-mocks
rspec-activemodel-mocks | RubyGems.org | your community gem host
your communityrspecactivemodelmocksrubygems
https://api.rubyonrails.org/v5.1.1/classes/ActiveModel/Callbacks.html
ActiveModel::Callbacks
activemodelcallbacks