code: public SharedAccessSignatureAuthorizationRuleInner getKeysForKeyName(String resourceGroupName, String resourceName, String keyName) {
          return getKeysForKeyNameWithServiceResponseAsync(resourceGroupName, resourceName, keyName).toBlocking().single().body();
      }
docs: Get a shared access policy by name from an IoT hub. For more information, see: https://docs.microsoft.com/azure/iot-hub/iot-hub-devguide-security.
  Get a shared access policy by name from an IoT hub. For more information, see: https://docs.microsoft.com/azure/iot-hub/iot-hub-devguide-security.
  
  @param resourceGroupName The name of the resource group that contains the IoT hub.
  @param resourceName The name of the IoT hub.
  @param keyName The name of the shared access policy.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @throws ErrorDetailsException thrown if the request is rejected by server
  @throws RuntimeException all other wrapped checked exceptions if the request fails to be sent
  @return the SharedAccessSignatureAuthorizationRuleInner object if successful.