Add method cast in ValueWrapper for automatically casting to python basic type
Add and pass unit test for cast method
Add examples and README
For the most efficient way, we should call cast in every iterable method over their items,
(e.g. calling cast in as_list() ). However, the returned type will change and cause incompatible.
So I try to preserve the if-else statement in a better way, and recursively call cast when _value is iterable
cast
inValueWrapper
for automatically casting to python basic typecast
method