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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 add_tuning(instrument, description, tuning):
 """Add a new tuning to the index. The instrument and description parameters should be strings; tuning should be a list of strings or a list of lists to denote courses. Example: """

    t = StringTuning(instrument, description, tuning)
    if _known.has_key(str.upper(instrument)):
        _known[str.upper(instrument)][1][str.upper(description)] = t
    else:
        _known[str.upper(instrument)] = (instrument,
                {str.upper(description): t})