if (! (obj instanceof FieldPosition))
if (this == obj) return true;  if (obj == null || obj.getClass() != this.getClass())
  public boolean equals (Object obj)  {    if (! (obj instanceof FieldPosition))      return false;    FieldPosition fp = (FieldPosition) obj;    return (field_id == fp.field_id	    && begin == fp.begin	    && end == fp.end);  }