public String moreToString(){
  StringBuilder sb=new StringBuilder("Last cert?  ");
  sb.append((index == -1) ? "Yes" : "No");
  sb.append("\n");
  return sb.toString();
}

public String moreToString ( ) { StringBuilder sb = new StringBuilder ( "Last cert?  " ) ; sb . append ( ( index == - 1 ) ? "Yes" : "No" ) ; sb . append ( "\n" ) ; return sb . toString ( ) ; }
return vertex index as string compatible with the way other vertex . xtostring ( ) methods display information .
