[Route("posts")]
public class PostController : ControllerBase
{
    // Without FluentRestBuilder
    // Will return a 404 StatusResult or a 200 OkObjectResult
    [HttpGet("{id}", Name = "PostResource")]
    public async Task<IActionResult> Get(int id)
    {
        var post = await this.dbContext.Posts
            .Include(p => p.Author)
            .SingleOrDefaultAsync(p => p.Id == id);
        if (post == null)
        {
            return this.NotFound();
        }

        var result = new PostResponse(post, this.Url);
        return this.Ok(result);
    }

    // With FluentRestBuilder
    // Will return a 404 StatusResult or a 200 OkObjectResult
    [HttpGet("{id}", Name = "PostResource")]
    public async Task<IActionResult> Get(int id) =>
        await this.CreateQueryableSingle<Post>()
            .Include(p => p.Author)
            .SingleOrDefaultAsync(p => p.Id == id)
            .NotFoundWhenNull()
            .Map(p => new PostResponse(p, this.Url))
            .ToOkObjectResult();

    // Without FluentRestBuilder
    [HttpPost("{id}")]
    public async Task<IActionResult> Update([FromBody] PostRequest request, int id)
    {
        var post = await this.dbContext.Posts
            .Include(p => p.Author)
            .SingleOrDefaultAsync(p => p.Id == id);
        if (post == null)
        {
            return this.NotFound();
        }

        if (!this.ModelState.IsValid)
        {
            return this.BadRequest(this.ModelState);
        }

        post.Title = request.Title;
        post.Content = request.Content;
        await this.dbContext.SaveChangesAsync();

        var result = new PostResponse(post, this.Url);
        return this.Ok(post);
    }

    // With FluentRestBuilder
    [HttpPost("{id}")]
    public async Task<IActionResult> Update([FromBody] PostRequest request, int id) =>
        await this.CreateEntitySingle<Post>(id)
            .NotFoundWhenNull()
            .BadRequestWhenModelStateIsInvalid(this.ModelState)
            .Do(p =>
            {
                p.Title = request.Title;
                p.Content = request.Content;
            })
            .SaveChangesAsync()
            .Map(p => new PostResponse(p, this.Url))
            .ToOkObjectResult();
}