<PackageReference Include="System.Security.Permissions" Version="9.0.5" />

FirstMatchCodeGroup

public sealed class FirstMatchCodeGroup : CodeGroup
Allows security policy to be defined by the union of the policy statement of a code group and that of the first child code group that matches. This class cannot be inherited.
namespace System.Security.Policy { [System.Obsolete("This type is obsolete. See https://go.microsoft.com/fwlink/?LinkID=155570 for more information.")] public sealed class FirstMatchCodeGroup : CodeGroup { public override string MergeLogic => null; public FirstMatchCodeGroup(IMembershipCondition membershipCondition, PolicyStatement policy) : base(null, null) { } public override CodeGroup Copy() { return null; } public override PolicyStatement Resolve(Evidence evidence) { return null; } public override CodeGroup ResolveMatchingCodeGroups(Evidence evidence) { return null; } } }