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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 _grains():
    '''
    Helper function to the grains from the proxied devices.
    '''
    client = _get_client()
    # This is a collection of the configuration of all running devices under NSO
    ret = client.get_datastore(DatastoreType.RUNNING)
    GRAINS_CACHE.update(ret)
    return GRAINS_CACHE