```ruby
require 'set'

module Joiner
  class AssociationNotFound < StandardError
  end
end

require 'joiner/joins'
require 'joiner/path'
```

Make sure ActiveRecord is loaded.
user
```ruby
require 'set'
require 'active_record'

module Joiner
  class AssociationNotFound < StandardError
  end
end

require 'joiner/joins'
require 'joiner/path'
```
assistant