```ruby
module ActiveModel
  module Validations
    module HelperMethods
      private
        def _merge_attributes(attr_names)
          options = attr_names.extract_options!.symbolize_keys
          attr_names.flatten!
          options[:attributes] = attr_names
          options
        end
    end
  end
end
```

Add nodoc to the Validations::Helpers
user
```ruby
module ActiveModel
  module Validations
    module HelperMethods # :nodoc:
      private
        def _merge_attributes(attr_names)
          options = attr_names.extract_options!.symbolize_keys
          attr_names.flatten!
          options[:attributes] = attr_names
          options
        end
    end
  end
end
```
assistant