Simple repository sample

using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;

namespace tacRepository
{
    public interface IDbSet<T>: IQueryable<T>
    {
        void Add(T data);
        void Remove(T data);
    }

    public interface IDbContext: IDisposable
    {
        IDbSet<T> GetDbSet<T>();
        void Attach<T>(T data);
        void SubmitChanges();
    }

    public class Person: IIdentifiableObject<Guid>
    {
        public Guid Id { get; set; }
        public string Name { get; set; }
    }

    public class Apartment: IIdentifiableObject<Guid>
    {
        public Guid Id { get; set; }
    }

    public interface IIdentifiableObject<out T>
        where T: struct
    {
        T Id { get; }
    }

    public class Repository<TData, TIdentifier>: IDisposable
        where TIdentifier : struct
        where TData : class, IIdentifiableObject<TIdentifier>
    {
        private readonly IDbContext _dbContext;

        public Repository(IDbContext dbContext)
        {
            _dbContext = dbContext;
        }

        public TData Load(TIdentifier id)
        {
            var result = _dbContext.GetDbSet<TData>().SingleOrDefault(d => d.Id == id);
            if (result == null)
                throw new ArgumentOutOfRangeException("id", id, "Object not found");
            return result;
        }

        public IEnumerable<TData> LoadAll()
        {
            return _dbContext.GetDbSet<TData>();
        }

        public IEnumerable<TData> Load(Expression<Func<TData, bool>> criteria)
        {
            return _dbContext.GetDbSet<TData>().Where(criteria);
        }

        public void Insert(TData data)
        {
            _dbContext.GetDbSet<TData>().Add(data);
            _dbContext.SubmitChanges();
        }

        public void Update(TData data)
        {
            _dbContext.Attach(data);
            _dbContext.SubmitChanges();
        }

        public void Delete(TData data)
        {
            _dbContext.GetDbSet<TData>().Remove(data);
            _dbContext.SubmitChanges();
        }

        public void Dispose()
        {
            _dbContext.Dispose();
        }
    }

    public class UsageSample
    {
        private readonly Repository<Person, Guid> _repository;

        public UsageSample(Repository<Person, Guid> repository)
        {
            _repository = repository;
        }

        public void PrintPersons()
        {
            foreach (var person in _repository.LoadAll())
            {
                Console.WriteLine(person.Name);
            }
        }

        public void AddPerson(string name)
        {
            var person = new Person
                {
                    Id = Guid.NewGuid(),
                    Name = name
                };
            _repository.Insert(person);
        }
    }
}