@Override
  public UnaryCallable<ListUsableWorkstationsRequest, ListUsableWorkstationsResponse>
      listUsableWorkstationsCallable() {
    return listUsableWorkstationsCallable;
  }
Constructs an instance of GrpcWorkstationsStub, using the given settings. This is protected so
that it is easy to make a subclass, but otherwise, the static factory methods should be
preferred.
java-workstations/google-cloud-workstations/src/main/java/com/google/cloud/workstations/v1beta/stub/GrpcWorkstationsStub.java