Some Code puzzle

codepuzzle.fs

Given the following definitions
    |>> :       map/fmap
    v:          NonEmptyList<SomeRecord>
    SomeRecord: {foo: Option<_>; bar: Option<_>; baz: Option<_>}
    isSomeList: SomeRecord -> List<bool, string>
        //string: the name of the field
        //bool: if Some then true else false

What does this code do?

    v
    |>> isSomeList
    |> concat
    |> List.countBy id
    |>> snd
    |> distinct
    |> length
    |> ((=) 1)