code: public Observable<VirtualNetworkRuleInner> createOrUpdateAsync(String resourceGroupName, String accountName, String virtualNetworkRuleName, CreateOrUpdateVirtualNetworkRuleParameters parameters) {
          return createOrUpdateWithServiceResponseAsync(resourceGroupName, accountName, virtualNetworkRuleName, parameters).map(new Func1<ServiceResponse<VirtualNetworkRuleInner>, VirtualNetworkRuleInner>() {
              @Override
              public VirtualNetworkRuleInner call(ServiceResponse<VirtualNetworkRuleInner> response) {
                  return response.body();
              }
          });
      }
docs: Creates or updates the specified virtual network rule. During update, the virtual network rule with the specified name will be replaced with this new virtual network rule.
  
  @param resourceGroupName The name of the Azure resource group.
  @param accountName The name of the Data Lake Store account.
  @param virtualNetworkRuleName The name of the virtual network rule to create or update.
  @param parameters Parameters supplied to create or update the virtual network rule.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the VirtualNetworkRuleInner object