code: public Observable<DeletedSecretBundle> deleteSecretAsync(String vaultBaseUrl, String secretName) {
          return deleteSecretWithServiceResponseAsync(vaultBaseUrl, secretName).map(new Func1<ServiceResponse<DeletedSecretBundle>, DeletedSecretBundle>() {
              @Override
              public DeletedSecretBundle call(ServiceResponse<DeletedSecretBundle> response) {
                  return response.body();
              }
          });
      }
docs: Deletes a secret from a specified key vault.
  The DELETE operation applies to any secret stored in Azure Key Vault. DELETE cannot be applied to an individual version of a secret. This operation requires the secrets/delete permission.
  
  @param vaultBaseUrl The vault name, for example https://myvault.vault.azure.net.
  @param secretName The name of the secret.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the DeletedSecretBundle object