<PackageReference Include="NETStandard.Library" Version="2.0.3" />

System.Xml.Schema.XmlSchemaDerivationMethod

namespace System.Xml.Schema { public enum XmlSchemaDerivationMethod { All = 255, Empty = 0, Extension = 2, List = 8, None = 256, Restriction = 4, Substitution = 1, Union = 16 } }