code: public final Cursor<T> queryByExample (Connection conn, T obj,
                                             FieldMask mask)
      {
          return new Cursor<T>(this, conn, obj, mask, false);
      }
docs: Select records from database table using <I>obj</I> object as template
  for selection.
  
  @param obj example object for search.
  @param mask field mask indicating which fields in the example object
  should be used when building the query.