* example:
   *
   * {@snippet :
   * CharMatcher.is('a').removeFrom("bazaar")
   * }
   *
   * ... returns {@code "bzr"}.
   */
  public String removeFrom(CharSequence sequence) {
    String string = sequence.toString();
    int pos = indexIn(string);
    if (pos == -1) {
      return string;
    }