i = buf.toString().indexOf (substring); if (i > -1) { buf.delete (i, i + substring.length()); deleted = true; }  return deleted;
return this;
    public boolean delete (String substring)    {        int      i;        boolean  deleted = false;        i = buf.toString().indexOf (substring);        if (i > -1)        {            buf.delete (i, i + substring.length());            deleted = true;        }        return deleted;    }