return s[i].literal < s[j].literal
	}
	return s[i].freq < s[j].freq
}

func (s byFreq) Swap(i, j int) { s[i], s[j] = s[j], s[i] }

func reverseBits(number uint16, bitLength byte) uint16 {
	return bits.Reverse16(number << (16 - bitLength))

  }

  /** Returns {@code true} if {@code x} represents a power of two. */
  public static boolean isPowerOfTwo(BigInteger x) {
    checkNotNull(x);
    return x.signum() > 0 && x.getLowestSetBit() == x.bitLength() - 1;
  }

  /**
   * Returns the base-2 logarithm of {@code x}, rounded according to the specified rounding mode.
   *
   * @throws IllegalArgumentException if {@code x <= 0}

		numCodegens--
	}
	header := 3 + 5 + 5 + 4 + (3 * numCodegens) +
		w.codegenEncoding.bitLength(w.codegenFreq[:]) +
		int(w.codegenFreq[16])*2 +
		int(w.codegenFreq[17])*3 +
		int(w.codegenFreq[18])*7
	size = header +
		litEnc.bitLength(w.literalFreq) +
		offEnc.bitLength(w.offsetFreq) +
		extraBits

	return size, numCodegens
}

  }

  /** Returns {@code true} if {@code x} represents a power of two. */
  public static boolean isPowerOfTwo(BigInteger x) {
    checkNotNull(x);
    return x.signum() > 0 && x.getLowestSetBit() == x.bitLength() - 1;
  }

  /**
   * Returns the base-2 logarithm of {@code x}, rounded according to the specified rounding mode.
   *
   * @throws IllegalArgumentException if {@code x <= 0}

  }

  static double bigToDouble(BigInteger x) {
    // This is an extremely fast implementation of BigInteger.doubleValue(). JDK patch pending.
    BigInteger absX = x.abs();
    int exponent = absX.bitLength() - 1;
    // exponent == floor(log2(abs(x)))
    if (exponent < Long.SIZE - 1) {
      return x.longValue();
    } else if (exponent > MAX_EXPONENT) {
      return x.signum() * POSITIVE_INFINITY;
    }

    /*

			t.Errorf("#%d: Incorrect error result (did fail? %v, expected: %v)", i, err == nil, test.ok)
		}
		if err == nil {
			if test.bitLength != ret.BitLength || !bytes.Equal(ret.Bytes, test.out) {
				t.Errorf("#%d: Bad result: %v (expected %v %v)", i, ret, test.out, test.bitLength)
			}
		}
	}
}

func TestBitStringAt(t *testing.T) {
	bs := BitString{[]byte{0x82, 0x40}, 16}
	if bs.At(0) != 1 {

  }

  static double bigToDouble(BigInteger x) {
    // This is an extremely fast implementation of BigInteger.doubleValue(). JDK patch pending.
    BigInteger absX = x.abs();
    int exponent = absX.bitLength() - 1;
    // exponent == floor(log2(abs(x)))
    if (exponent < Long.SIZE - 1) {
      return x.longValue();
    } else if (exponent > MAX_EXPONENT) {
      return x.signum() * POSITIVE_INFINITY;
    }

    /*

// valid bits is recorded. Padding bits will be zero.
type BitString struct {
	Bytes     []byte // bits packed into bytes.
	BitLength int    // length in bits.
}

// At returns the bit at the given index. If the index is out of range it
// returns 0.
func (b BitString) At(i int) int {
	if i < 0 || i >= b.BitLength {
		return 0
	}
	x := i / 8
	y := 7 - uint(i%8)
	return int(b.Bytes[x]>>y) & 1
}

		return nil, err
	}

	pkix := pkixPublicKey{
		Algo: publicKeyAlgorithm,
		BitString: asn1.BitString{
			Bytes:     publicKeyBytes,
			BitLength: 8 * len(publicKeyBytes),
		},
	}

	ret, _ := asn1.Marshal(pkix)
	return ret, nil
}

// These structures reflect the ASN.1 structure of X.509 certificates.:

type certificate struct {

   */
  public static UnsignedInteger valueOf(BigInteger value) {
    checkNotNull(value);
    checkArgument(
        value.signum() >= 0 && value.bitLength() <= Integer.SIZE,
        "value (%s) is outside the range for an unsigned integer value",
        value);
    return fromIntBits(value.intValue());
  }

  /**