public String getSecret(String key) {
    String normalizedKey = normalize(key);
    SecretBundle secretBundle = vaultClient.getSecret(vaultUrl, normalizedKey);
    return secretBundle == null ? null : secretBundle.value();
  }
A secrets store backed by Azure Key Vault.
extensions/cloud/portability-cloud-microsoft/src/main/java/org/datatransferproject/cloud/microsoft/cosmos/AzureKeyVaultStore.java