public void remove() {
      checkRemove(false);
    }
  }

  /**
   * Returns the empty {@code Iterator} that throws {@link IllegalStateException} instead of {@link
   * UnsupportedOperationException} on a call to {@link Iterator#remove()}.
   */
  // Casting to any type is safe since there are no actual elements.
  @SuppressWarnings("unchecked")
  static <T extends @Nullable Object> Iterator<T> emptyModifiableIterator() {

    public void remove() {
      checkRemove(false);
    }
  }

  /**
   * Returns the empty {@code Iterator} that throws {@link IllegalStateException} instead of {@link
   * UnsupportedOperationException} on a call to {@link Iterator#remove()}.
   */
  // Casting to any type is safe since there are no actual elements.
  @SuppressWarnings("unchecked")
  static <T extends @Nullable Object> Iterator<T> emptyModifiableIterator() {