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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 processQueryString(self, s):
 """ See CoverSource.processQueryString. """

    char_blacklist = set(string.punctuation)
    char_blacklist.remove("'")
    char_blacklist.remove("&")
    char_blacklist = frozenset(char_blacklist)
    return __class__.unpunctuate(s.lower(), char_blacklist=char_blacklist)