AngleSharp by Florian Rappl

<PackageReference Include="AngleSharp" Version="0.8.1" />

 DomLenientThisAttribute

public sealed class DomLenientThisAttribute : Attribute
The attribute indicates that invocations of the attribute's getter or setter with a this value that is not an object that implements the interface on which the attribute appears will be ignored.
using System; namespace AngleSharp.Attributes { [AttributeUsage(AttributeTargets.Property | AttributeTargets.Event)] public sealed class DomLenientThisAttribute : Attribute { internal DomLenientThisAttribute() { } } }