<PackageReference Include="System.Reactive" Version="6.0.1" />

System.Reactive.Linq.ObservableImpl.Join<TLeft, TRight, TLeftDuration, TRightDuration, TResult>

sealed class Join<TLeft, TRight, TLeftDuration, TRightDuration, TResult> : Producer<TResult, _<TLeft, TRight, TLeftDuration, TRightDuration, TResult>>
public Join(IObservable<TLeft> left, IObservable<TRight> right, Func<TLeft, IObservable<TLeftDuration>> leftDurationSelector, Func<TRight, IObservable<TRightDuration>> rightDurationSelector, Func<TLeft, TRight, TResult> resultSelector)