<PackageReference Include="System.Security.Permissions" Version="10.0.0-preview.4.25258.110" />

FileIOPermissionAccess

Specifies the type of file access requested.
namespace System.Security.Permissions { [Flags] public enum FileIOPermissionAccess { AllAccess = 15, Append = 4, NoAccess = 0, PathDiscovery = 8, Read = 1, Write = 2 } }