code: @Override
      public Object touch(Object coll, Collection.Key key) throws PageException {
  	Object o = getCollection(coll, key, null);
  	if (o != null) return o;
  	return set(coll, key, new StructImpl());
      }
docs: /*
  public Object touch(Object coll, String key) throws PageException { Object
  o=getCollection(coll,key,null); if(o!=null) return o; return set(coll,key,new StructImpl()); }