```ruby
module PrimaryAttachment
  extend ActiveSupport::Concern
  include ApplicationHelper

  def picture?
    picture.present? && picture.online
  end

  def picture_medium
    picture.image.url(:medium) if picture?
  end
end
```

Add top level documentation for concerns
user
```ruby
#
# == PrimaryAttachment Concerns
#
module PrimaryAttachment
  extend ActiveSupport::Concern
  include ApplicationHelper

  def picture?
    picture.present? && picture.online
  end

  def picture_medium
    picture.image.url(:medium) if picture?
  end
end
```
assistant