user.rb
action_store :x, :xx, class_name: 'A::B'
action-store/lib/action_store/mixin.rb line 37
klass_name = opts[:class_name] || name.to_s.classify
# defined_actions => [{target_type: 'A::B', ...}]
User.create.create_action(:x, Xx.create)
action-store/lib/action_store/mixin.rb line 29
name = target_type.to_s.singularize.underscore
# name = 'A/B'
# find_defined_action(:x, 'A::B') => nil