Sorted Stream Graph(排序流图)

例子

[one-fourth-first][/one-fourth-first]
[one-fourth][/one-fourth]
[one-fourth][/one-fourth]
[one-fourth][/one-fourth]

[one-fourth-first][/one-fourth-first]
[one-fourth][/one-fourth]
[one-fourth][/one-fourth]
[one-fourth][/one-fourth]