code: function newSSEClientFactory(endpoint) {
      return function(initDict) {
          initDict = initDict || { };
          // get URI options
          var uriOptions = utils.getURIOptions(initDict);
          utils.removeURIOptions(initDict);
          // create a new URI
          var uri = utils.url(endpoint, uriOptions);
          // get auth options
          var authOptions = utils.getAuthOptions([utils.setup(), this, initDict]);
          // sign the URI (automatically removes the secret param from initDict)
          auth.sign(authOptions.key, authOptions.secret, uri);
          // determine whether to use an eventsource or poll the endpoint
          return new EventSource(uri.toString(), initDict);
      };
  }
docs: Return a function that returns a SSE client
  
  @param  {Endpoint} endpoint
  @return {SSEClientFactory}
  @throws Error