private static boolean allProperDefsInFragment(int[] defs, int ref, LinkedHashSet<Integer> fragmentInstructions, int[] postorder) {
    for (int def : defs) {
      if (!fragmentInstructions.contains(def) && postorder[def] < postorder[ref]) return false;
    }

    return true;
  }
private static boolean allProperDefsInFragment(int[] defs, int ref, LinkedHashSet<Integer> fragmentInstructions, int[] postorder)