#### Description

Detect junction which needs to split.

e.g:

![](https://camo.githubusercontent.com/1d799ea8bb23fcc4295a36c810722d6403ff1a5b/68747470733a2f2f64326d787565667165616137736a2e636c6f756466726f6e742e6e65742f735f433035373736464242433035354335463046464145393743413331383336394439383331303037364533344533353731374333413330353645454135324245375f313530313036393237333033345f53637265656e2b53686f742b323031372d30372d32362b61742b352e30372e33332b504d2e706e67)