.Net核心2.2中Linq语句的模拟单元测试总是返回null

public interface IRepository
{
    IEnumerable<string> GetData();
}

public class Repository : IRepository
{
    private readonly List<string> _data = new List<string> { "Item1", "Item2", "Item3" };

    public IEnumerable<string> GetData()
    {
        return _data.Where(item => item.Contains("1"));
    }
}

[Test]
public void TestGetData()
{
    // 创建模拟对象
    var mockRepository = new Mock<IRepository>();
    
    // 设置模拟对象的行为
    mockRepository.Setup(repo => repo.GetData()).Returns(new List<string> { "Item1", "AnotherItem1" });
    
    // 使用模拟对象
    var repository = mockRepository.Object;
    
    // 执行LINQ查询并触发执行
    var result = repository.GetData().ToList(); // 注意这里的ToList()调用
    
    // 断言结果
    Assert.AreEqual(2, result.Count);
    Assert.IsTrue(result.Contains("Item1"));
    Assert.IsTrue(result.Contains("AnotherItem1"));
}