Testing fluent mappings in linq to lucene

LinqLuceneTest.cs

using System.Linq;
using Lucene.Net.Linq;
using Lucene.Net.Linq.Fluent;
using Lucene.Net.Store;
using Lucene.Net.Util;
using NUnit.Framework;

namespace LinqLuceneTest
{
    public class Customer
    {
        public int Id { get; set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }
    }

    [TestFixture]
    public class FluentLuceneTest
    {
        private readonly Customer[] customers =
            {
                new Customer { Id = 1, FirstName = "Alice", LastName = "Anderson" },
                new Customer { Id = 2, FirstName = "Bob", LastName = "Anderson" },
                new Customer { Id = 3, FirstName = "Charlie", LastName = "Anderson" },
                new Customer { Id = 4, FirstName = "Donald", LastName = "Duck" }
            };

        public class CustomerMap : ClassMap<Customer>
        {
            public CustomerMap()
                : base(Version.LUCENE_30)
            {
                Key(x => x.Id);
                Property(x => x.FirstName);
                Property(x => x.LastName);
            }
        }
            
        [Test]
        public void Can_Get_Results_When_Using_Fluent_Mappings()
        {
            var map = new CustomerMap();
            
            using (var directory = new RAMDirectory())
            using (var provider = new LuceneDataProvider(directory, Version.LUCENE_30))
            {
                provider.Settings.EnableMultipleEntities = false;

                var mapper = map.ToDocumentMapper();
                using (var session = provider.OpenSession(mapper))
                {
                    session.Add(this.customers);
                }

                using (var session = provider.OpenSession(mapper))
                {
                    var query = session.Query().Where(x => x.LastName == "Anderson");
                    var results = query.ToList();

                    Assert.AreEqual(3, results.Count);
                }
            }
        }
    }

    
}