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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 disambiguate(names, mark='1'):
 """ Given a list of strings ``names``, return a new list of names where repeated names have been disambiguated by repeatedly appending the given mark. EXAMPLE:: ['sing', 'song', 'sing1', 'sing11'] """

    names_seen = set()
    new_names = []
    for name in names:
        new_name = name
        while new_name in names_seen:
            new_name += mark
        new_names.append(new_name)
        names_seen.add(new_name)

    return new_names