public void WhenUnregisteringATypeGenericallyItShouldUnregisterAllInstancesOfThatType()
{
// Arrange
var container = new ShifterContainer();
container
.AddInstance(typeof(int), 1234)
.AddInstance(typeof(string), "Hello")
.AddInstance(typeof(int), 2)
.AddInstance(typeof(IShifterContainer), ShifterContainer.Default);
// Act
container.Unregister <int>();
var resolvedInts = container.ResolveAll <int>();
var resolvedString = container.ResolveAll <string>();
var resolvedContainer = container.ResolveAll <IShifterContainer>();
// Assert
resolvedInts.Should().BeEmpty("because these are unregistered.");
resolvedString.Count().Should().Be(1, "because one string was left.");
resolvedContainer.Count().Should().Be(1, "because one IShifterContainer was left.");
}