public static Task <IEntity> GetById(this IEntityService entityService, IEntityDefinition entityDefinition, object id, CancellationToken ct)
{
entityService.NotNull(nameof(entityService));
entityDefinition.NotNull(nameof(entityDefinition));
id.NotNull(nameof(id));
return(entityService.CreateQuery(entityDefinition).Add(Criterion.IdEq(id)).UniqueResult <IEntity>(ct));
}