code: public CognitiveServicesAccountKeysInner regenerateKey(String resourceGroupName, String accountName) {
          return regenerateKeyWithServiceResponseAsync(resourceGroupName, accountName).toBlocking().single().body();
      }
docs: Regenerates the specified account key for the specified Cognitive Services account.
  
  @param resourceGroupName The name of the resource group within the user's subscription.
  @param accountName The name of the cognitive services account within the specified resource group. Cognitive Services account names must be between 3 and 24 characters in length and use numbers and lower-case letters only.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @throws ErrorException thrown if the request is rejected by server
  @throws RuntimeException all other wrapped checked exceptions if the request fails to be sent
  @return the CognitiveServicesAccountKeysInner object if successful.