public String toString() {
        String rankTypeName = rankType == null ? "(none)" : rankType.name();
        return "index '" + name +
               "' [ranktype: " + rankTypeName +
               ", prefix: " + prefix + "]";
    }
Returns a read-only iterator of the aliases (Strings) to this index name
config-model/src/main/java/com/yahoo/schema/Index.java