<PackageReference Include="System.Reactive" Version="4.1.2" />

QueryablePlan<TResult>

public class QueryablePlan<TResult>
Represents an execution plan for join patterns represented by an expression tree.
using System.Linq.Expressions; namespace System.Reactive.Joins { public class QueryablePlan<TResult> { public Expression Expression { get; } internal QueryablePlan(Expression expression) { Expression = expression; } } }