<PackageReference Include="System.Reactive" Version="6.0.0-preview.13" />

System.Reactive.Linq.IQbservableProvider

public interface IQbservableProvider
Defines methods to create and execute queries that are described by an IQbservable object.
namespace System.Reactive.Linq { public interface IQbservableProvider { IQbservable<TResult> CreateQuery<[System.Runtime.CompilerServices.Nullable(2)] TResult>(Expression expression); } }