code: public Splitter trim(char[] chars) {
      Matcher matcher = new CharsMatcher(chars);
      return new Splitter(pairSeparator, keyValueSeparator, matcher, matcher);
    }
docs: Returns a splitter that removes all leading or trailing characters
  matching the given characters from each returned key and value.
  
  @param chars characters
  @return a splitter with the desired configuration