code: public Observable<FirewallRuleInner> createOrUpdateFirewallRuleAsync(String resourceGroupName, String accountName, String name, FirewallRuleInner parameters) {
          return createOrUpdateFirewallRuleWithServiceResponseAsync(resourceGroupName, accountName, name, parameters).map(new Func1<ServiceResponse<FirewallRuleInner>, FirewallRuleInner>() {
              @Override
              public FirewallRuleInner call(ServiceResponse<FirewallRuleInner> response) {
                  return response.body();
              }
          });
      }
docs: Creates or updates the specified firewall rule.
  
  @param resourceGroupName The name of the Azure resource group that contains the Data Lake Store account.
  @param accountName The name of the Data Lake Store account to which to add the firewall rule.
  @param name The name of the firewall rule to create or update.
  @param parameters Parameters supplied to create the create firewall rule.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the FirewallRuleInner object