code: public ServiceFuture<List<RecordSetInner>> listByTypeAsync(final String resourceGroupName, final String zoneName, final RecordType recordType, final ListOperationCallback<RecordSetInner> serviceCallback) {
          return AzureServiceFuture.fromPageResponse(
              listByTypeSinglePageAsync(resourceGroupName, zoneName, recordType),
              new Func1<String, Observable<ServiceResponse<Page<RecordSetInner>>>>() {
                  @Override
                  public Observable<ServiceResponse<Page<RecordSetInner>>> call(String nextPageLink) {
                      return listByTypeNextSinglePageAsync(nextPageLink);
                  }
              },
              serviceCallback);
      }
docs: Lists the record sets of a specified type in a DNS zone.
  
  @param resourceGroupName The name of the resource group.
  @param zoneName The name of the DNS zone (without a terminating dot).
  @param recordType The type of record sets to enumerate. Possible values include: 'A', 'AAAA', 'CNAME', 'MX', 'NS', 'PTR', 'SOA', 'SRV', 'TXT'
  @param serviceCallback the async ServiceCallback to handle successful and failed responses.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the {@link ServiceFuture} object