public void addAttribute(AttributeInfo info){
  if (attribute == null)   attribute=new ArrayList();
  AttributeInfo.remove(attribute,info.getName());
  attribute.add(info);
}

public void addAttribute ( AttributeInfo info ) { if ( attribute == null ) attribute = new ArrayList ( ) ; AttributeInfo . remove ( attribute , info . getName ( ) ) ; attribute . add ( info ) ; }
appends an attribute . if there is already an attribute with the same name , the new one substitutes for it .
