namespace Microsoft.IdentityModel.Tokens
{
    public delegate IEnumerable<SecurityKey> TokenDecryptionKeyResolver(string token, SecurityToken securityToken, string kid, TokenValidationParameters validationParameters);
    {
        public virtual IAsyncResult BeginInvoke(string token, SecurityToken securityToken, string kid, TokenValidationParameters validationParameters, AsyncCallback callback, object object);
    }
}