public async Task <Key> RotateSecretAsync(Contracts.Data.Secret secret, CancellationToken token)
        {
            if (null == secret)
            {
                throw new ArgumentNullException(nameof(secret));
            }
            if (secret.SecretType == Contracts.Data.SecretType.Attached)
            {
                if (null == secret.Configuration)
                {
                    throw new ArgumentNullException(nameof(secret.Configuration));
                }
                if (null == secret.Configuration.Policy)
                {
                    throw new ArgumentException(nameof(secret.Configuration.Policy));
                }
            }
            Key result = null;

            if (secret.SecretType == Contracts.Data.SecretType.Attached)
            {
                result = await OnRotateSecretAsync(secret, token);
            }
            else
            {
                result = new Key()
                {
                }
            };

            if (null != result)
            {
                result.SecretVersion = await PersistSecretToVaultAsync(secret, result.Value, token);

                result.Value = "********************************";
                if (string.IsNullOrWhiteSpace(result.SecretVersion))
                {
                    //todo: change exception type to something more meaningful
                    throw new InvalidOperationException("Unable to store newly generated value in vault.");
                }
            }

            return(result);
        }
 protected abstract Task <string> OnPersistSecretToVaultAsync(Contracts.Data.Secret secret, string value, CancellationToken token);
 protected abstract Task <Key> OnRotateSecretAsync(Contracts.Data.Secret secret, CancellationToken token);
 protected async Task <string> PersistSecretToVaultAsync(Contracts.Data.Secret secret, string value, CancellationToken token)
 {
     return(await OnPersistSecretToVaultAsync(secret, value, token));
 }