Src Instance Dest Instance Span   Frontier Timestamp
1            2             {b-c}  1970-01-01 00:00:00.000000002 +0000 UTC
2            1             {a-b}  1970-01-01 00:00:00.000000001 +0000 UTC
3            3             d{-'}  1970-01-01 00:00:00.000000002 +0000 UTC
3            3             {d'-e} 1970-01-01 00:00:00 +0000 UTC
