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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def generate_secured_key(value, key_nonce_separator='.', nonce_length=4, base=BASE62):
 """ Generate a secured key composed of the integer value encoded in Base62 and a nonce. @param value: an integer value. @param key_nonce_separator: the character that is used to separate the key and the nonce to form the secured key. @param nonce_length: the number of characters to compose the nonce. @param base: a sequence of characters that is used to encode the integer value. @return: a tuple ``(key, nonce, secured_key)``: * ``key``: string representation of the integer value in Base62. * ``nonce``: "number used once", a pseudo-random number to ensure that the key cannot be reused in replay attacks. * ``secured_key``: a string composed of the key concatenated with the nonce. """

    if not isinstance(value, (int, long)):
        raise ValueError()

    posix_time = int(time.mktime(datetime.datetime.now().timetuple()))
    nonce = hashlib.md5(str(posix_time)).hexdigest()[:nonce_length]
    key = int_to_key(value, base=base)
    return key, nonce, '%s%s%s' % (key, key_nonce_separator, nonce)