define
set a 1
snapshot 1
set b 2
snapshot 2
set c 3
snapshot 3
----

iter snapshot=1
first
next
prev
----
a:1
.
a:1

iter snapshot=2
first
next
next
prev
----
a:1
b:2
.
b:2

iter snapshot=3
first
next
next
next
prev
----
a:1
b:2
c:3
.
c:3

define
set a 1
snapshot 1
set a 2
snapshot 2
set a 3
snapshot 3
----

iter snapshot=1
first
next
prev
----
a:1
.
a:1

iter snapshot=2
first
next
prev
----
a:2
.
a:2

iter snapshot=3
first
next
prev
----
a:3
.
a:3

define
set a 1
snapshot 1
set a 2
snapshot 2
set a 3
snapshot 3
compact a-b
----

iter snapshot=1
first
next
prev
----
a:1
.
a:1

iter snapshot=2
first
next
prev
----
a:2
.
a:2

iter snapshot=3
first
next
prev
----
a:3
.
a:3

define
merge a 1
snapshot 1
merge a 2
snapshot 2
merge a 3
snapshot 3
compact a-b
----

iter snapshot=1
first
next
prev
----
a:1
.
a:1

iter snapshot=2
first
next
prev
----
a:12
.
a:12

iter snapshot=3
first
next
prev
----
a:123
.
a:123
