anchor.diff:  
       firstOlympicCity.Name |> should equal "Athens"
   
  -
   [<Test>]
   let ``Can execute query that checks for not null``() =
       let p = query {
  
positive.code: 
  let findCountryByFifaCode code = 
      query { for x in data.``Time and Space``.Location.Countries do 
              where (x.``FIFA Code`` = code) 
              exactlyOne }
  
  [<Test>]
  
negative.code:         for p in data.Commons.People.Persons do
          select (p.Name, p.``Date of birth``)
      } |> Seq.head |> should equal ("Jack Abramoff", "1958-02-28")
  
  [<Test>]
  let ``Can handle Ghana multiple ISO 3 codes``() =
      let ghana = data.``Time and Space``.Location.Countries.Individuals.Ghana
      ghana.``ISO Alpha 3`` |> Seq.toArray |> should equal [|"GHA"; "GH"|]
  