<PackageReference Include="NETStandard.Library" Version="2.0.0-preview2-25401-01" />

System.Xml.Serialization.XmlMapping

public abstract class XmlMapping
namespace System.Xml.Serialization { public abstract class XmlMapping { public string ElementName { get; } public string Namespace { get; } public string XsdElementName { get; } public void SetKey(string key); } }