anchor.diff:    /// Use `getCollectionNames` instead
     @deprecated
     Future<List<String>> listCollections() {
  -    return _collectionsInfoCursor().stream.map((map) => map['name'].split('.')).where((arr)=> arr.length == 2).map((arr)=> arr.last).toList();
  +    return _collectionsInfoCursor().map((map) => map['name'].split('.')).where((arr)=> arr.length == 2).map((arr)=> arr.last).toList();
     }
   
     
  
positive.code:     if (collectionName != null) {
        selector['ns'] = '$databaseName.$collectionName';
      }
      return new Cursor(this, new DbCollection(this, DbCommand.SYSTEM_INDEX_COLLECTION), selector).toList();
    }
    
    String _createIndexName(Map keys) {
  
negative.code:   }
    
    Future<List<String>> getCollectionNames([Map filter = const {}]) {
        return _listCollectionsCursor(filter).map((map) => map['name']).toList();
    }
      
    
  