code: func (w *IndexWriter) AddDocumentWithAnalyzer(doc []IndexableField, analyzer analysis.Analyzer) error {
  	return w.UpdateDocument(nil, doc, analyzer)
  }
docs: /*
  Adds a document to this index, using the provided analyzer instead of
  the value of Analyzer().
  
  See AddDocument() for details on index and IndexWriter state after an
  error, and flushing/merging temporary free space requirements.
  
  NOTE: if this method hits a memory issue, you hsould immediately
  close the writer. See above for details.
  */