code: public Observable<ReplicationInner> createAsync(String resourceGroupName, String registryName, String replicationName, ReplicationInner replication) {
          return createWithServiceResponseAsync(resourceGroupName, registryName, replicationName, replication).map(new Func1<ServiceResponse<ReplicationInner>, ReplicationInner>() {
              @Override
              public ReplicationInner call(ServiceResponse<ReplicationInner> response) {
                  return response.body();
              }
          });
      }
docs: Creates a replication for a container registry with the specified parameters.
  
  @param resourceGroupName The name of the resource group to which the container registry belongs.
  @param registryName The name of the container registry.
  @param replicationName The name of the replication.
  @param replication The parameters for creating a replication.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable for the request