* or trailing characters matching the given {@code CharMatcher} from each returned substring. For
   * example, {@code Splitter.on(',').trimResults(CharMatcher.is('_')).split("_a ,_b_ ,c__")}
   * returns an iterable containing {@code ["a ", "b_ ", "c"]}.
   *
   * @param trimmer a {@link CharMatcher} that determines whether a character should be removed from
   *     the beginning/end of a subsequence

   * or trailing characters matching the given {@code CharMatcher} from each returned substring. For
   * example, {@code Splitter.on(',').trimResults(CharMatcher.is('_')).split("_a ,_b_ ,c__")}
   * returns an iterable containing {@code ["a ", "b_ ", "c"]}.
   *
   * @param trimmer a {@link CharMatcher} that determines whether a character should be removed from
   *     the beginning/end of a subsequence