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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 from_ivorn(cls, ivorn, nside=256):
 """ Creates a `~mocpy.moc.MOC` object from a given ivorn. Parameters ivorn : str nside : int, optional 256 by default Returns ------- result : `~mocpy.moc.MOC` The resulting MOC. """

        return cls.from_url('%s?%s' % (MOC.MOC_SERVER_ROOT_URL,
                                       urlencode({
                                           'ivorn': ivorn,
                                           'get': 'moc',
                                           'order': int(np.log2(nside))
                                       })))