testWriteTo{fileOps{int64(1), "abc", int64(2), "defgh", int64(4)}, 15, errUnrefData},
			testRead{100, "", errUnrefData},
			testRemaining{0, 5},
		},
	}}

	for i, v := range vectors {
		var fr fileReader
		switch maker := v.maker.(type) {
		case makeReg:
			r := testNonEmptyReader{strings.NewReader(maker.str)}
			fr = &regFileReader{r, maker.size}
		case makeSparse: