/// <summary>Find out if a principal has a certain permission by default.</summary>
/// <param name="user">The principal to check for allowance.</param>
/// <param name="permission">The type of permission to map against.</param>
/// <returns>True if the system is configured to allow the user to the given permission.</returns>
public virtual bool IsAuthorized(IPrincipal user, Permission permission)
{
return((Administrators.MapsTo(permission) && Administrators.Contains(user)) ||
(Editors.MapsTo(permission) && Editors.Contains(user)) ||
(Writers.MapsTo(permission) && Writers.Contains(user)));
}