code: public Observable<Page<FirewallRuleInner>> listFirewallRulesAsync(final String resourceGroupName, final String accountName) {
          return listFirewallRulesWithServiceResponseAsync(resourceGroupName, accountName)
              .map(new Func1<ServiceResponse<Page<FirewallRuleInner>>, Page<FirewallRuleInner>>() {
                  @Override
                  public Page<FirewallRuleInner> call(ServiceResponse<Page<FirewallRuleInner>> response) {
                      return response.body();
                  }
              });
      }
docs: Lists the Data Lake Store firewall rules within the specified Data Lake Store account.
  
  @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 from which to get the firewall rules.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the PagedList&lt;FirewallRuleInner&gt; object