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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 get_zip_class():
 """ Supplement ZipFile class to support context manager for Python 2.6 """

    class ContextualZipFile(zipfile.ZipFile):
        def __enter__(self):
            return self
        def __exit__(self, type, value, traceback):
            self.close
    return zipfile.ZipFile if hasattr(zipfile.ZipFile, '__exit__') else \
        ContextualZipFile