after the promotion function, I spend about two days to fix bugs. there are some problem I've got.
1.trust original code, there are some bugs that out of imagination.
2.can not ensure the function what I wrote.
3.afraid can not design a good pattern. always in thinking.
make a change, write the better function code and find the problem quickly. make the mind clear.
the end, make the life more health and more tolerant.