public void normalize(){
  StringBuilder sb=new StringBuilder();
  for (  String v : values) {
    sb.append(v);
  }
  values.clear();
  values.add(sb.toString());
  compacted=false;
}

public void normalize ( ) { StringBuilder sb = new StringBuilder ( ) ; for ( String v : values ) { sb . append ( v ) ; } values . clear ( ) ; values . add ( sb . toString ( ) ) ; compacted = false ; }
this method convert the list of values again into a only one value . after that the attribute is not compacted . todo : what about entities , now are just appended " abcd . . . & 20 ; . . . cc "
