public HashMap<String, String> getDefaultFSAs() {
       HashMap<String, String> defaultDicts = new HashMap<>();
       defaultDicts.put(GENERIC_EXPAND_DICT, GENERIC_EXPAND_DICT_FILENAME);
       return defaultDicts;
   }
Get default FSA dictionary names

@return Pair of FSA dictionary name and filename
container-search/src/main/java/com/yahoo/search/query/rewrite/rewriters/GenericExpansionRewriter.java