<PackageReference Include="NETStandard.Library" Version="2.0.0" />

System.ComponentModel.Design.Serialization.MemberRelationshipService

public abstract class MemberRelationshipService
public MemberRelationship this[MemberRelationship source] { get; set; }

public MemberRelationship this[object sourceOwner, MemberDescriptor sourceMember] { get; set; }

protected virtual void SetRelationship(MemberRelationship source, MemberRelationship relationship)

public abstract bool SupportsRelationship(MemberRelationship source, MemberRelationship relationship)