看extjs的doc，发现这个注释里的图示，求助是什么工具做的。

index=2
removeCount=2
/=====\
+---+---+---+---+---+---+---+---+
| 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
+---+---+---+---+---+---+---+---+
/ \/ \/ \/ \
/ /\ /\ /\ \
/ / \/ \/ \ +--------------------------+
/ / /\ /\ +--------------------------+ \
/ / / \/ +--------------------------+ \ \
/ / / /+--------------------------+ \ \ \
/ / / / \ \ \ \
v v v v v v v v
+---+---+---+---+---+---+ +---+---+---+---+---+---+---+---+---+
| 0 | 1 | 4 | 5 | 6 | 7 | | 0 | 1 | a | b | c | 4 | 5 | 6 | 7 |
+---+---+---+---+---+---+ +---+---+---+---+---+---+---+---+---+
A B \=========/
insert=[a,b,c]

如果纯手打，这人也太闲的蛋疼了吧。