/**
   * Get the sub-list of passes for the job between passes <code>begin</code> and <code>end</code>,
   * inclusive.
   */
  public List passes(Job job, Pass.ID begin, Pass.ID end) {
    List l = passes(job);
    Pass p = null;

    Iterator i = l.iterator();

    while (i.hasNext()) {
      p = (Pass) i.next();
      if (begin == p.id()) break;
      if (!(p instanceof BarrierPass)) i.remove();
    }

    while (p.id() != end && i.hasNext()) {
      p = (Pass) i.next();
    }

    while (i.hasNext()) {
      p = (Pass) i.next();
      i.remove();
    }

    return l;
  }