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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 vault_relation_complete(backend=None):
 """Determine whether vault relation is complete :param backend: Name of secrets backend requested :ptype backend: string :returns: whether the relation to vault is complete :rtype: bool"""

    vault_kv = VaultKVContext(secret_backend=backend or VAULTLOCKER_BACKEND)
    vault_kv()
    return vault_kv.complete