output: #fixed code
                                  @Override
      @SuppressWarnings("unchecked")
      public void forEachRemaining(Consumer<? super E> action) {
          Objects.requireNonNull(action);
          int hi = getFence();
          Object[] a = array;
          int i;
          for (i = index, index = hi; i < hi; i++) {
              action.accept((E) a[i]);
          }
          if (getModCount(list) != expectedModCount) {
              throw new ConcurrentModificationException();
          }
      }
input: #vulnerable code 
                                  @Override
      @SuppressWarnings("unchecked")
      public void forEachRemaining(Consumer<? super E> action) {
          Objects.requireNonNull(action);
          int i, hi; // hoist accesses and checks from loop
          Vector<E> lst = list;
          Object[] a;
          if ((hi = fence) < 0) {
              synchronized (lst) {
                  expectedModCount = getModCount(lst);
                  a = array = getData(lst);
                  hi = fence = getSize(lst);
              }
          } else {
              a = array;
          }
          if (a != null && (i = index) >= 0 && (index = hi) <= a.length) {
              while (i < hi) {
                  action.accept((E) a[i++]);
              }
              if (expectedModCount == getModCount(lst)) {
                  return;
              }
          }
          throw new ConcurrentModificationException();
      } 
                              #location 21 
                              #vulnerability type THREAD_SAFETY_VIOLATION