public void FlatMapToDifferentType()
{
var one = Failable <int, bool> .Success(1);
Failable <string, bool> onePlusOne = one.FlatMap(i => Failable <string, bool> .Success($"{i}+1=2"));
Assert.That(onePlusOne.OrThrow(), Is.EqualTo("1+1=2"));
}