public Throwable(Throwable throwable){
  this();
  this.detailMessage=throwable == null ? null : throwable.toString();
  cause=throwable;
}

public Throwable ( Throwable throwable ) { this ( ) ; this . detailMessage = throwable == null ? null : throwable . toString ( ) ; cause = throwable ; }
constructs a new instance of this class with its walkback and cause filled in .
