protected void setNames(Set<String> names)
   {
      this.names.clear();
      this.indexes.clear();
      this.names.addAll(names);
      this.indexes.addAll(names);
      // new list of indexes if thought to be up to date
      dirty = false;
   }
protected void setNames ( Set < String > names ) { this . names . clear ( ) ; this . indexes . clear ( ) ; this . names . addAll ( names ) ; this . indexes . addAll ( names ) ; dirty = false ; }
Sets new names, clearing existing. It is thought to be used when list of indexes can
be externally changed.

@param names