Iterator<T> removeFrom, Predicate<? super T> predicate) {
    checkNotNull(predicate);
    boolean modified = false;
    while (removeFrom.hasNext()) {
      if (predicate.apply(removeFrom.next())) {
        removeFrom.remove();
        modified = true;
      }
    }
    return modified;
  }

  /**
   * Traverses an iterator and removes every element that does not belong to the provided

      Iterator<T> removeFrom, Predicate<? super T> predicate) {
    checkNotNull(predicate);
    boolean modified = false;
    while (removeFrom.hasNext()) {
      if (predicate.apply(removeFrom.next())) {
        removeFrom.remove();
        modified = true;
      }
    }
    return modified;
  }

  /**
   * Traverses an iterator and removes every element that does not belong to the provided