Grape Swagger does not show up Example param

I'm using grape-swagger gem to produce swagger documentation for dredd.

I have such params:

params do
  requires :id, type: Integer, documentation: { x: { example: 1 } }
end

Grape swagger ignores example param.
Instead of this:

{
  "in": "path",
  "name": "id",
  "type": "integer",
  "format": "int32",
  "required": true,
  "x-example": 1
}

I got this:

{
  "in": "path",
  "name": "id",
  "type": "integer",
  "format": "int32",
  "required": true
}

How to send example values for test purposes?

I found this in dredd issues. This solves my problem. In a nutshell, the solution looks like this:

module MyApp
  module AddExampleToBodyParam
    module ClassMethods
      private

      def document_description(settings)
        super
        @parsed_param[:example] = settings[:example] if settings[:example]
      end
    end

    def self.prepended(base)
      class << base
        prepend ClassMethods
      end
    end
  end
end

module GrapeSwagger
  module DocMethods
    class ParseParams
      prepend MyApp::AddExampleToBodyParam
    end
  end
end

Now,I can proxy example value to params body with this:

expose :some, documentation: { example: 'test' }