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