code: function createAuth(type, token) {
  
    if (!type) {
      throw new Error('<type> required');
    }
  
    if (!token) {
      throw new Error('<token> required');
    }
  
    /**
     * Actual middleware that appends a `Authorization: "${type} ${token}"`
     * header to the request options.
     */
    return function(worker) {
  
      const workerOptions = worker.options;
      const requestOptions = workerOptions.requestOptions || {};
      const headers = requestOptions.headers || {};
  
      worker.options = {
        ...workerOptions,
        requestOptions: {
          ...requestOptions,
          headers: {
            ...headers,
            Authorization: `${type} ${token}`
          }
        }
      };
    };
  }
docs: Set arbitrary authorization tokens on Engine API requests.
  
  @example
  
  Worker(engineEndpoint, {
  use: [
  Auth('Bearer', 'BEARER_TOKEN')
  ]
  });