var b bytes.Buffer
	b.Grow(64)
	b.Write([]byte("abcde"))
	rdbuf := make([]byte, 1)
	n, err := b.Read(rdbuf)
	if err != nil {
		panic(err)
	}
	fmt.Println(n)
	fmt.Println(b.String())
	fmt.Println(string(rdbuf))
	// Output:
	// 1
	// bcde
	// a
}

func ExampleBuffer_ReadByte() {
	var b bytes.Buffer
	b.Grow(64)
	b.Write([]byte("abcde"))
	c, err := b.ReadByte()
	if err != nil {

			testRemaining{6, 3},
			testReadFrom{fileOps{int64(3), "cde"}, 6, nil},
			testRemaining{0, 0},
		},
	}, {
		maker: makeSparse{makeReg{5, "abcde"}, sparseHoles{{2, 3}}, 8},
		tests: []testFnc{
			testReadFrom{fileOps{"ab", int64(3), "cde"}, 8, nil},
			testRemaining{0, 0},
		},
	}, {
		maker: makeSparse{makeReg{5, "abcde"}, sparseHoles{{2, 3}}, 8},
		tests: []testFnc{

//		{Offset: 21, Length: 4},  // Hole fragment for 21..24
//	}
//
// Then the content of the resulting sparse file with a Header.Size of 25 is:
//
//	var sparseFile = "\x00"*2 + "abcde" + "\x00"*11 + "fgh" + "\x00"*4
type (
	sparseDatas []sparseEntry
	sparseHoles []sparseEntry
)

// validateSparseEntries reports whether sp is a valid sparse map.