code: public static CharPredicate isChar(final char c) {
      return new CharPredicate() {
        @Override public boolean isChar(char x) {
          return x == c;
        }
        @Override public String toString() {
          return Character.toString(c);
        }
      };
    }
docs: A {@link CharPredicate} that returns true if the character is equal to {@code c}.