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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 _get_encoding(encoding_or_label):
 """ Accept either an encoding object or label. :param encoding: An :class:`Encoding` object or a label string. :returns: An :class:`Encoding` object. :raises: :exc:`~exceptions.LookupError` for an unknown label. """

    if hasattr(encoding_or_label, 'codec_info'):
        return encoding_or_label

    encoding = lookup(encoding_or_label)
    if encoding is None:
        raise LookupError('Unknown encoding label: %r' % encoding_or_label)
    return encoding