for _, test := range sortTests {
		got := sprint(test.data)
		if got != test.print {
			t.Errorf("%s: got %q, want %q", reflect.TypeOf(test.data), got, test.print)
		}
	}
}

func TestInterface(t *testing.T) {
	// A map containing multiple concrete types should be sorted by type,
	// then value. However, the relative ordering of types is unspecified,
	// so test this by checking the presence of sorted subgroups.