code: public Observable<NetworkSecurityGroupInner> createOrUpdateAsync(String resourceGroupName, String networkSecurityGroupName, NetworkSecurityGroupInner parameters) {
          return createOrUpdateWithServiceResponseAsync(resourceGroupName, networkSecurityGroupName, parameters).map(new Func1<ServiceResponse<NetworkSecurityGroupInner>, NetworkSecurityGroupInner>() {
              @Override
              public NetworkSecurityGroupInner call(ServiceResponse<NetworkSecurityGroupInner> response) {
                  return response.body();
              }
          });
      }
docs: Creates or updates a network security group in the specified resource group.
  
  @param resourceGroupName The name of the resource group.
  @param networkSecurityGroupName The name of the network security group.
  @param parameters Parameters supplied to the create or update network security group operation.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable for the request