<PackageReference Include="System.Reactive" Version="7.0.0-preview.16" />

System.Reactive.Joins.Pattern<TSource1, TSource2, TSource3, TSource4, TSource5, TSource6, TSource7, TSource8, TSource9>

public class Pattern<TSource1, TSource2, TSource3, TSource4, TSource5, TSource6, TSource7, TSource8, TSource9> : Pattern
namespace System.Reactive.Linq.ObservableImpl { }