code: func (c *Conn) NewBulkIndexerErrors(maxConns, retrySeconds int) *BulkIndexer {
  	b := c.NewBulkIndexer(maxConns)
  	b.RetryForSeconds = retrySeconds
  	b.ErrorChannel = make(chan *ErrorBuffer, 20)
  	return b
  }
docs: // A bulk indexer with more control over error handling
  //    @maxConns is the max number of in flight http requests
  //    @retrySeconds is # of seconds to wait before retrying falied requests
  //
  //   done := make(chan bool)
  //   BulkIndexerGlobalRun(100, done)