<PackageReference Include="NETStandard.Library" Version="2.0.3" />

System.Threading.Tasks.TaskCanceledException

namespace System.Threading.Tasks { public class TaskCanceledException : OperationCanceledException { public Task Task { get; } public TaskCanceledException(); protected TaskCanceledException(SerializationInfo info, StreamingContext context); public TaskCanceledException(string message); public TaskCanceledException(string message, Exception innerException); public TaskCanceledException(Task task); } }