def as_json(options = {})
      {}.tap do |result|
        result[:body] = @body unless @body.nil?
        result[:headers] = @headers unless @headers.nil?
        result[:status] = @status unless @status.nil?
      end
    end
def as_json(options = {})
      {}.tap do |result|
        result[:body] = @body unless @body.nil?
        result[:headers] = @headers unless @headers.nil?
        result[:status] = @status unless @status.nil?
      end
    end
Public: create a new response representation from a Rack-compatible
 response (e.g. [status, headers, response_object]).
 Public: convert the response to JSON.  nil values are ignored.