code: public Observable<SyncAgentInner> beginCreateOrUpdateAsync(String resourceGroupName, String serverName, String syncAgentName, String syncDatabaseId) {
          return beginCreateOrUpdateWithServiceResponseAsync(resourceGroupName, serverName, syncAgentName, syncDatabaseId).map(new Func1<ServiceResponse<SyncAgentInner>, SyncAgentInner>() {
              @Override
              public SyncAgentInner call(ServiceResponse<SyncAgentInner> response) {
                  return response.body();
              }
          });
      }
docs: Creates or updates a sync agent.
  
  @param resourceGroupName The name of the resource group that contains the resource. You can obtain this value from the Azure Resource Manager API or the portal.
  @param serverName The name of the server on which the sync agent is hosted.
  @param syncAgentName The name of the sync agent.
  @param syncDatabaseId ARM resource id of the sync database in the sync agent.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the SyncAgentInner object