```ruby
class Api::ApplicationController < ActionController::Base
  protect_from_forgery with: :null_session

  def serialization_scope
    view_context
  end

  def current_site
    @current_site ||= Site.where(opened: true).find_by!(fqdn: params[:site_fqdn])
  end
end
```

Add missing `private` specification to internal method
user
```ruby
class Api::ApplicationController < ActionController::Base
  protect_from_forgery with: :null_session

  private

  def serialization_scope
    view_context
  end

  def current_site
    @current_site ||= Site.where(opened: true).find_by!(fqdn: params[:site_fqdn])
  end
end
```
assistant