code: public Observable<CertificateInner> createOrUpdateAsync(String resourceGroupName, String automationAccountName, String certificateName, CertificateCreateOrUpdateParameters parameters) {
          return createOrUpdateWithServiceResponseAsync(resourceGroupName, automationAccountName, certificateName, parameters).map(new Func1<ServiceResponse<CertificateInner>, CertificateInner>() {
              @Override
              public CertificateInner call(ServiceResponse<CertificateInner> response) {
                  return response.body();
              }
          });
      }
docs: Create a certificate.
  
  @param resourceGroupName Name of an Azure Resource group.
  @param automationAccountName The name of the automation account.
  @param certificateName The parameters supplied to the create or update certificate operation.
  @param parameters The parameters supplied to the create or update certificate operation.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the CertificateInner object