code: public Observable<HybridRunbookWorkerGroupInner> updateAsync(String resourceGroupName, String automationAccountName, String hybridRunbookWorkerGroupName, RunAsCredentialAssociationProperty credential) {
          return updateWithServiceResponseAsync(resourceGroupName, automationAccountName, hybridRunbookWorkerGroupName, credential).map(new Func1<ServiceResponse<HybridRunbookWorkerGroupInner>, HybridRunbookWorkerGroupInner>() {
              @Override
              public HybridRunbookWorkerGroupInner call(ServiceResponse<HybridRunbookWorkerGroupInner> response) {
                  return response.body();
              }
          });
      }
docs: Update a hybrid runbook worker group.
  
  @param resourceGroupName Name of an Azure Resource group.
  @param automationAccountName The name of the automation account.
  @param hybridRunbookWorkerGroupName The hybrid runbook worker group name
  @param credential Sets the credential of a worker group.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the HybridRunbookWorkerGroupInner object