# File lib/dragonfly/routed_endpoint.rb, line 15
    def call(env)
      params = Utils.symbolize_keys Rack::Request.new(env).params
      value = @block.call(params.merge(routing_params(env)), @app, env)
      case value
      when nil then plain_response(404, "Not Found")
      when Job, Model::Attachment
        job = value.is_a?(Model::Attachment) ? value.job : value
        Response.new(job, env).to_response
      else
        Dragonfly.warn("can't handle return value from routed endpoint: #{value.inspect}")
        plain_response(500, "Server Error")
      end
    rescue Job::NoSHAGiven
      plain_response(400, "You need to give a SHA parameter")
    rescue Job::IncorrectSHA
      plain_response(400, "The SHA parameter you gave is incorrect")
    end