private static <T>T reportJoin(Object r){
  if (r instanceof AltResult) {
    Throwable x;
    if ((x=((AltResult)r).ex) == null)     return null;
    if (x instanceof CancellationException)     throw (CancellationException)x;
    if (x instanceof CompletionException)     throw (CompletionException)x;
    throw new CompletionException(x);
  }
  @SuppressWarnings("unchecked") T t=(T)r;
  return t;
}

private static < T > T reportJoin ( Object r ) { if ( r instanceof AltResult ) { Throwable x ; if ( ( x = ( ( AltResult ) r ) . ex ) == null ) return null ; if ( x instanceof CancellationException ) throw ( CancellationException ) x ; if ( x instanceof CompletionException ) throw ( CompletionException ) x ; throw new CompletionException ( x ) ; } @ SuppressWarnings ( "unchecked" ) T t = ( T ) r ; return t ; }
decodes outcome to return result or throw unchecked exception .
