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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(self, key):
    '''Return the object named by key or None if it does not exist.
       CacheShimDatastore first checks its ``cache_datastore``.
    '''
    value = self.cache_datastore.get(key)
    return value if value is not None else self.child_datastore.get(key)