* java.util.regex (where we want them in order to avoid catastrophic backtracking).
     */
    String decimal = "(?:\\d+#(?:\\.\\d*#)?|\\.\\d+#)";
    String completeDec = decimal + "(?:[eE][+-]?\\d+#)?[fFdD]?";
    String hex = "(?:[0-9a-fA-F]+#(?:\\.[0-9a-fA-F]*#)?|\\.[0-9a-fA-F]+#)";
    String completeHex = "0[xX]" + hex + "[pP][+-]?\\d+#[fFdD]?";

        radix);
    // Benchmarks indicate this is probably not worth optimizing.
    return Integer.toString(toInt(x), radix);
  }

  /**
   * Returns the unsigned {@code byte} value represented by the given decimal string.
   *
   * @throws NumberFormatException if the string does not contain a valid unsigned {@code byte}
   *     value
   * @throws NullPointerException if {@code string} is null (in contrast to {@link