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

System.Xml.Linq.XNamespace

public sealed class XNamespace
namespace System.Xml.Linq { public sealed class XNamespace { public string NamespaceName { get; } public static XNamespace None { get; } public static XNamespace Xml { get; } public static XNamespace Xmlns { get; } public static XNamespace Get(string namespaceName); public XName GetName(string localName); public static XName operator +(XNamespace ns, string localName); public static bool operator ==(XNamespace left, XNamespace right); public static implicit operator XNamespace(string namespaceName); public static bool operator !=(XNamespace left, XNamespace right); } }