code: function makeGraphics(agent) {
      return function (id) {
          if (id === undefined) {
              return agent.request('get_universe_graphics', undefined);
          }
          else {
              return new GraphicImpl(agent, id);
          }
      };
  }
docs: Create a new {@link Graphics} instance that uses the given `agent` to
  make its HTTP requests to the ESI interface.
  
  @param agent The agent making actual requests
  @returns A Graphics API instance