code: public static CharMatcher is(final char match) {
      return new FastMatcher() {
        @Override public boolean matches(char c) {
          return c == match;
        }
  
        @Override public String replaceFrom(CharSequence sequence, char replacement) {
          return sequence.toString().replace(match, replacement);
        }
  
        @Override public CharMatcher and(CharMatcher other) {
          return other.matches(match) ? this : NONE;
        }
  
        @Override public CharMatcher or(CharMatcher other) {
          return other.matches(match) ? other : super.or(other);
        }
  
        @Override public CharMatcher negate() {
          return isNot(match);
        }
  
        @Override public String toString() {
          return "CharMatcher.is('" + showCharacter(match) + "')";
        }
      };
    }
docs: Returns a {@code char} matcher that matches only one specified character.