tr := NewReader(f)
	_, err = tr.Read([]byte{})
	if err == nil || err != io.EOF {
		t.Errorf("Unexpected error: %v, wanted %v", err, io.EOF)
	}

}

type reader struct{ io.Reader }
type readSeeker struct{ io.ReadSeeker }
type readBadSeeker struct{ io.ReadSeeker }

func (rbs *readBadSeeker) Seek(int64, int) (int64, error) { return 0, fmt.Errorf("illegal seek") }