这玩艺可以serialize function, lambda 等一众pickle不能序列化的东西。
还可以把当前的continuation 给序列化了。
https://pypi.python.org/pypi/dill
Dill extends python’s ‘pickle’ module for serializing and
de-serializing python objects to the majority of the built-in python
types. Serialization is the process of converting an object to a byte
stream, and the inverse of which is converting a byte stream back to
on python object hierarchy.