code: public BsonDocument asDocument() {
          BsonDocument document = new BsonDocument();
  
          addW(document);
  
          addWTimeout(document);
          addFSync(document);
          addJ(document);
  
          return document;
      }
docs: Gets this write concern as a document.
  
  @return The write concern as a BsonDocument, even if {@code w &lt;= 0}