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
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