public class CSharp4118Tests : Linq3IntegrationTest
{
    [Fact]
    public void Test()
    {
        var collection = GetCollection<C>();
        var queryable = collection.AsQueryable()
            .Select(x => new { S = "abc", HasId = x.Id != "000000000000000000000000" });

        var stages = Translate(collection,queryable);

        AssertStages(stages, "{ $project : { S : 'abc', HasId : { $ne : ['$_id', ObjectId('000000000000000000000000')] }, _id : 0 } }")
    } 

    private class C
    {
        [BsonRepresentation(BsonType.ObjectId)] public string Id { get; set; }
    }
}