public async Task GetByIdAsyncWithSpecification_ShouldApplySpecification()
{
// Arrange
TestEntity[] entities = _fixture.CreateMany <TestEntity>(2).ToArray();
var dbContextMock = new DbContextMock <TestDbContext>(_options);
dbContextMock.CreateDbSetMock(x => x.TestEntities, (x, _) => (x.Id), entities);
var repository = new ReadRepository <TestEntity, Guid>(() => dbContextMock.Object);
var specification = new Mock <ISpecification <TestEntity> >();
// Act
TestEntity result = await repository.GetSingleWithSpecificationAsync(specification.Object);
// Assert
result.Should().NotBeNull();
result.Should().BeOfType(typeof(TestEntity));
}