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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 to_text(value):
 """Convert a DNS rdata class to text. @param value: the rdata class value @type value: int @rtype: string @raises ValueError: the rdata class value is not >= 0 and <= 65535 """


    if value < 0 or value > 65535:
        raise ValueError("class must be between >= 0 and <= 65535")
    text = _by_value.get(value)
    if text is None:
        text = 'CLASS' + repr(value)
    return text