AngleSharp by Florian Rappl

<PackageReference Include="AngleSharp" Version="0.2.2" />

 DOMStringMap

public sealed class DOMStringMap : DOMCollection
Represents a list of DOMTokens.
public string this[string name] { get; set; }

Gets or sets the value for a specified property.

public string GetDataAttr(string prop)

Gets the value for a specified property.

public bool HasDataAttr(string prop)

Checks if the specified property has been set.

public DOMStringMap RemoveDataAttr(string prop)

Removes the given property from the list of attributes.

public DOMStringMap SetDataAttr(string prop, string value)

Sets the value of the specified property.