System.Text.Encoding.CodePages by Microsoft

<PackageReference Include="System.Text.Encoding.CodePages" Version="7.0.0-preview.2.22152.2" />

 GeneratedDllImportAttribute

namespace System.Runtime.InteropServices { [AttributeUsage(AttributeTargets.Method, AllowMultiple = false, Inherited = false)] internal sealed class GeneratedDllImportAttribute : Attribute { public CharSet CharSet { get; set; } public string EntryPoint { get; set; } public bool ExactSpelling { get; set; } public bool SetLastError { get; set; } public string LibraryName { get; set; } public GeneratedDllImportAttribute(string dllName) { LibraryName = dllName; } } }