class HexString {

    private static final char[] HEX_ARRAY = "0123456789abcdef".toCharArray();

    /** Constructor */
    private HexString() {
        // DO NOTHING
    }

    /**
     * Method to convert a byte array to a lowercase hexadecimal String
     *
     * @param bytes bytes
     * @return the return value
     */
    public static String toHex(byte[] bytes) {<FILL_FUNCTION_BODY>}
}

        char[] hexChars = new char[bytes.length * 2];
        for (int i = 0, j = 0; i < bytes.length; i++) {
            hexChars[j++] = HEX_ARRAY[(0xF0 & bytes[i]) >>> 4];
            hexChars[j++] = HEX_ARRAY[0x0F & bytes[i]];
        }
        return new String(hexChars).toLowerCase();
    
<no_super_class>