code: public ServiceFuture<CertificateInner> createOrUpdateAsync(String resourceGroupName, String name, CertificateInner certificateEnvelope, final ServiceCallback<CertificateInner> serviceCallback) {
          return ServiceFuture.fromResponse(createOrUpdateWithServiceResponseAsync(resourceGroupName, name, certificateEnvelope), serviceCallback);
      }
docs: Create or update a certificate.
  Create or update a certificate.
  
  @param resourceGroupName Name of the resource group to which the resource belongs.
  @param name Name of the certificate.
  @param certificateEnvelope Details of certificate, if it exists already.
  @param serviceCallback the async ServiceCallback to handle successful and failed responses.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the {@link ServiceFuture} object