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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 retrieve_secret_id(url, token):
 """Retrieve a response-wrapped secret_id from Vault :param url: URL to Vault Server :ptype url: str :param token: One shot Token to use :ptype token: str :returns: secret_id to use for Vault Access :rtype: str"""

    import hvac
    client = hvac.Client(url=url, token=token)
    response = client._post('/v1/sys/wrapping/unwrap')
    if response.status_code == 200:
        data = response.json()
        return data['data']['secret_id']