namespace System.Net.Http
{
    public sealed class HttpRequestOptions : ICollection<KeyValuePair<string!, object?>>, IDictionary<string!, object?>, IEnumerable, IEnumerable<KeyValuePair<string!, object?>>, IReadOnlyCollection<KeyValuePair<string!, object?>>, IReadOnlyDictionary<string!, object?>
    {
        public void Set<TValue>(HttpRequestOptionsKey<TValue> key, TValue value);
    }
}