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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 indexes(dic, keys=None):
 """ index dictionary by multiple keys Parameters dic : dict keys : list Examples -------- 'A' """

    keys = [] if keys is None else keys

    assert hasattr(dic, 'keys')
    new = dic.copy()
    old_key = None
    for key in keys:
        if not hasattr(new, 'keys'):
            raise KeyError('No indexes after: {}'.format(old_key))
        old_key = key
        new = new[key]
    return new