code: func (b *BulkIndexer) Index(index string, _type string, id, parent, ttl string, date *time.Time, data interface{}) error {
  	//{ "index" : { "_index" : "test", "_type" : "type1", "_id" : "1" } }
  	by, err := WriteBulkBytes("index", index, _type, id, parent, ttl, date, data)
  	if err != nil {
  		return err
  	}
  	b.bulkChannel <- by
  	return nil
  }
docs: // The index bulk API adds or updates a typed JSON document to a specific index, making it searchable.
  // it operates by buffering requests, and ocassionally flushing to elasticsearch
  // http://www.elasticsearch.org/guide/reference/api/bulk.html