namespace Microsoft.AspNetCore.Authentication
{
    public abstract class SignInAuthenticationHandler<TOptions> : SignOutAuthenticationHandler<TOptions!>, IAuthenticationHandler, IAuthenticationSignInHandler, IAuthenticationSignOutHandler
        where TOptions, new(), AuthenticationSchemeOptions!
    {
        public virtual Task! SignInAsync(ClaimsPrincipal! user, AuthenticationProperties? properties);
    }
}