checkLocation(where, len); txt.array = this.content;
if (where + len > count) throw new BadLocationException("Invalid location", where + len); txt.array = content;
  public void getChars(int where, int len, Segment txt)     throws BadLocationException  {    checkLocation(where, len);        txt.array = this.content;        txt.offset = where;        txt.count = len;      }