@Override
            public ApiFuture<ListUsableWorkstationsPagedResponse> getFuturePagedResponse(
                UnaryCallable<ListUsableWorkstationsRequest, ListUsableWorkstationsResponse>
                    callable,
                ListUsableWorkstationsRequest request,
                ApiCallContext context,
                ApiFuture<ListUsableWorkstationsResponse> futureResponse) {
              PageContext<
                      ListUsableWorkstationsRequest, ListUsableWorkstationsResponse, Workstation>
                  pageContext =
                      PageContext.create(
                          callable, LIST_USABLE_WORKSTATIONS_PAGE_STR_DESC, request, context);
              return ListUsableWorkstationsPagedResponse.createAsync(pageContext, futureResponse);
            }
The default scopes of the service.
java-workstations/google-cloud-workstations/src/main/java/com/google/cloud/workstations/v1/stub/WorkstationsStubSettings.java