{Offset: 1e10, Length: 1e10 - 100},
							{Offset: 2e10, Length: 1e10 - 100},
							{Offset: 3e10, Length: 1e10 - 100},
							{Offset: 4e10, Length: 1e10 - 100},
							{Offset: 5e10, Length: 1e10 - 100},
						},
					}, nil},
					testReadFrom{fileOps{
						int64(1e10 - blockSize),
						strings.Repeat("\x00", blockSize-100) + strings.Repeat("0123456789", 10),
						int64(1e10 - blockSize),