code: public boolean contains(final char ch) {
          for (final CharRange range : set) {
              if (range.contains(ch)) {
                  return true;
              }
          }
          return false;
      }
docs: <p>Does the {@code CharSet} contain the specified
  character {@code ch}.</p>
  
  @param ch  the character to check for
  @return {@code true} if the set contains the characters