Created by Jerry Wang, last modified on May 08, 2015
Customizing里针对transaction type WCBC和 item category group NORM有TAN和TAE两个item category：
Item category dropdown list的determine - filtering 逻辑Created by Jerry Wang, last modified on May 08, 2015 但是runtime时，dropdown list里只有1个entry TAN：
Item category dropdown list的determine - filtering 逻辑Created by Jerry Wang, last modified on May 08, 2015 Item category dropdown list的determine - filtering 逻辑Created by Jerry Wang, last modified on May 08, 2015 如何分析TAE被filter out的原因：
1. 找到item category绑定的field name：
Item category dropdown list的determine - filtering 逻辑Created by Jerry Wang, last modified on May 08, 2015 2. 查看GET_V的实现：
Item category dropdown list的determine - filtering 逻辑Created by Jerry Wang, last modified on May 08, 2015 设置断点，debug：
Item category dropdown list的determine - filtering 逻辑Created by Jerry Wang, last modified on May 08, 2015 读取order对应的orgamization model：
Item category dropdown list的determine - filtering 逻辑Created by Jerry Wang, last modified on May 08, 2015 得到sales org和distribution channel：
Item category dropdown list的determine - filtering 逻辑Created by Jerry Wang, last modified on May 08, 2015 拿到该product 的item category group:
Item category dropdown list的determine - filtering 逻辑Created by Jerry Wang, last modified on May 08, 2015 3. 这里的design是，根据process type和item category group唯一determine出一个item category：
即SPRO里如下图highlight的entry：
Item category dropdown list的determine - filtering 逻辑Created by Jerry Wang, last modified on May 08, 2015 对于TAE，因为其entry对应的main item category维护了值TAC，因此不会被line 225的FM所return。
Item category dropdown list的determine - filtering 逻辑Created by Jerry Wang, last modified on May 08, 2015 
