if err != nil {
		t.Errorf("read error: %v", err)
	}
	if n != 0 {
		t.Errorf("wrong count; got %d want 0", n)
	}
}

func TestUnreadByte(t *testing.T) {
	b := new(Buffer)

	// check at EOF
	if err := b.UnreadByte(); err == nil {
		t.Fatal("UnreadByte at EOF: got no error")
	}
	if _, err := b.ReadByte(); err == nil {
		t.Fatal("ReadByte at EOF: got no error")
	}