var testString string // test data for write tests
var testBytes []byte  // test data; same as testString but as a slice.

type negativeReader struct{}

func (r *negativeReader) Read([]byte) (int, error) { return -1, nil }

func init() {
	testBytes = make([]byte, N)
	for i := 0; i < N; i++ {
		testBytes[i] = 'a' + byte(i%26)
	}
	testString = string(testBytes)
}

// Verify that contents of buf match the string s.

	}
	wg.Wait()
}

func TestReaderWriteTo(t *testing.T) {
	for i := 0; i < 30; i += 3 {
		var l int
		if i > 0 {
			l = len(testString) / i
		}
		s := testString[:l]
		r := NewReader(testBytes[:l])
		var b Buffer
		n, err := r.WriteTo(&b)
		if expect := int64(len(s)); n != expect {
			t.Errorf("got %v; want %v", n, expect)
		}
		if err != nil {