// and that the data is correct.

			w.Reset()
			buf := NewWriterSize(w, bs)
			context := fmt.Sprintf("nwrite=%d bufsize=%d", nwrite, bs)
			n, e1 := buf.Write(data[0:nwrite])
			if e1 != nil || n != nwrite {
				t.Errorf("%s: buf.Write %d = %d, %v", context, nwrite, n, e1)
				continue
			}
			if e := buf.Flush(); e != nil {
				t.Errorf("%s: buf.Flush = %v", context, e)
			}

			written := w.Bytes()