def _call( env )
      env.merge! "rack.lodash" => {"organisation" => @organisation}

      request = Rack::Request.new(env.dup)
      if request.path_info == @http_path_to_lodash
        response = Rack::Response.new
        # for caching
        response.headers.merge! caching_headers( LODASH_FILE_NAME, LODASH_VERSION_DATE)

        # There's no need to test if the IF_MODIFIED_SINCE against the release date because the header will only be passed if the file was previously accessed by the requester, and the file is never updated. If it is updated then it is accessed by a different path.
        if request.env['HTTP_IF_MODIFIED_SINCE']
          response.status = 304
        else
          response.status = 200
          response.write ::File.read( ::File.expand_path "../../../vendor/assets/javascript/libs/lodash/#{LODASH_VERSION}/lodash.min.js", __FILE__)
        end
        response.finish
      else
        @app.call(env)
      end
    end
def _call( env )
      env.merge! "rack.lodash" => {"organisation" => @organisation}

      request = Rack::Request.new(env.dup)
      if request.path_info == @http_path_to_lodash
        response = Rack::Response.new
        # for caching
        response.headers.merge! caching_headers( LODASH_FILE_NAME, LODASH_VERSION_DATE)

        # There's no need to test if the IF_MODIFIED_SINCE against the release date because the header will only be passed if the file was previously accessed by the requester, and the file is never updated. If it is updated then it is accessed by a different path.
        if request.env['HTTP_IF_MODIFIED_SINCE']
          response.status = 304
        else
          response.status = 200
          response.write ::File.read( ::File.expand_path "../../../vendor/assets/javascript/libs/lodash/#{LODASH_VERSION}/lodash.min.js", __FILE__)
        end
        response.finish
      else
        @app.call(env)
      end
    end
For thread safety
 @param (see #call)