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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 mom_version(name='marathon-user'):
 """Returns the version of marathon on marathon. """

    if service_available_predicate(name):
        with marathon_on_marathon(name):
                return marathon_version()
    else:
        # We can either skip the corresponding test by returning False
        # or raise an exception.
        print('WARN: {} MoM not found. Version is None'.format(name))
        return None