defer func() {
		if err := recover(); err == nil {
			t.Fatal("Truncate(-1) should have panicked")
		}
	}()
	var b Buffer
	b.Truncate(-1)
}

func TestBufferTruncateOutOfRange(t *testing.T) {
	defer func() {
		if err := recover(); err == nil {
			t.Fatal("Truncate(20) should have panicked")
		}
	}()
	var b Buffer
	b.Write(make([]byte, 10))
	b.Truncate(20)