code: public Object touch(int row) throws PageException {
  	Object o = query.getAt(columnName, row, NullSupportHelper.NULL());
  	if (o != NullSupportHelper.NULL()) return o;
  	return query.setAt(columnName, row, new StructImpl());
      }
docs: touch a value, means if key dosent exist, it will created
  
  @param row
  @return matching value or created value
  @throws PageException