<PackageReference Include="Google.Protobuf" Version="3.35.1" />

Google.Protobuf.Reflection.PackageDescriptor

Represents a package in the symbol table. We use PackageDescriptors just as placeholders so that someone cannot define, say, a message type that has the same name as an existing package.
namespace Google.Protobuf.Reflection { internal sealed class PackageDescriptor : IDescriptor { public string Name { get; } public string FullName { get; } public FileDescriptor File { get; } } }