<PackageReference Include="NETStandard.Library" Version="2.0.2" />

System.AggregateException

public class AggregateException : Exception
namespace System { public class AggregateException : Exception { public ReadOnlyCollection<Exception> InnerExceptions { get; } public AggregateException(); public AggregateException(IEnumerable<Exception> innerExceptions); public AggregateException(params Exception[] innerExceptions); protected AggregateException(SerializationInfo info, StreamingContext context); public AggregateException(string message); public AggregateException(string message, IEnumerable<Exception> innerExceptions); public AggregateException(string message, Exception innerException); public AggregateException(string message, params Exception[] innerExceptions); public AggregateException Flatten(); public void Handle(Func<Exception, bool> predicate); } }