}
      }
    }
  }

  public void testDivideByZeroThrows() {
    for (long a : TEST_LONGS) {
      assertThrows(
          ArithmeticException.class,
          () -> UnsignedLong.fromLongBits(a).dividedBy(UnsignedLong.ZERO));
    }
  }

  public void testMod() {
    for (long a : TEST_LONGS) {
      for (long b : TEST_LONGS) {

      this.name = checkNotNull(name);
      this.chars = checkNotNull(chars);
      try {
        this.bitsPerChar = log2(chars.length, UNNECESSARY);
      } catch (ArithmeticException e) {
        throw new IllegalArgumentException("Illegal alphabet length " + chars.length, e);
      }

      // Compute how input bytes are chunked. For example, with base64 we chunk every 3 bytes into