code: public Observable<KeyBundle> importKeyAsync(String vaultBaseUrl, String keyName, JsonWebKey key) {
          return importKeyWithServiceResponseAsync(vaultBaseUrl, keyName, key).map(new Func1<ServiceResponse<KeyBundle>, KeyBundle>() {
              @Override
              public KeyBundle call(ServiceResponse<KeyBundle> response) {
                  return response.body();
              }
          });
      }
docs: Imports an externally created key, stores it, and returns key parameters and attributes to the client.
  The import key operation may be used to import any key type into an Azure Key Vault. If the named key already exists, Azure Key Vault creates a new version of the key. This operation requires the keys/import permission.
  
  @param vaultBaseUrl The vault name, for example https://myvault.vault.azure.net.
  @param keyName Name for the imported key.
  @param key The Json web key
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the KeyBundle object