}

		for j, tf := range v.tests {
			switch tf := tf.(type) {
			case testRead:
				b := make([]byte, tf.cnt)
				n, err := fr.Read(b)
				if got := string(b[:n]); got != tf.wantStr || err != tf.wantErr {
					t.Errorf("test %d.%d, Read(%d):\ngot  (%q, %v)\nwant (%q, %v)", i, j, tf.cnt, got, err, tf.wantStr, tf.wantErr)
				}
			case testWriteTo:

		}

		for j, tf := range v.tests {
			switch tf := tf.(type) {
			case testWrite:
				got, err := fw.Write([]byte(tf.str))
				if got != tf.wantCnt || err != tf.wantErr {
					t.Errorf("test %d.%d, Write(%s):\ngot  (%d, %v)\nwant (%d, %v)", i, j, tf.str, got, err, tf.wantCnt, tf.wantErr)
				}
			case testReadFrom:
				f := &testFile{ops: tf.ops}
				got, err := fw.ReadFrom(f)