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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_versions(source):
 """Return information about the Python versions required for specific features. The return value is a dictionary with keys as a version number as a tuple (for example Python 2.6 is (2,6)) and the value are a list of features that require the indicated Python version. """

    tree = compiler.parse(source)
    checker = compiler.walk(tree, NodeChecker())
    return checker.vers