def send_file(streamer, content_type, headers = {})
      return not_found if streamer.nil?

      headers['Content-Type'] = content_type
      headers['Last-Modified'] = streamer.mtime.httpdate

      [200, headers, streamer]
    end
def send_file(streamer, content_type, headers = {})
      return not_found if streamer.nil?

      headers['Content-Type'] = content_type
      headers['Last-Modified'] = streamer.mtime.httpdate

      [200, headers, streamer]
    end
Produces a Rack response that wraps the output from the Git adapter.

 A 404 response is produced if _streamer_ is +nil+.  Otherwise a 200
 response is produced with _streamer_ as the response body.

 @param [FileStreamer,IOStreamer] streamer a provider of content for the
   response body.
 @param [String] content_type the MIME type of the content.
 @param [Hash] headers additional headers to include in the response.

 @return a Rack response object.