<filename>type_cast/type_cast_9.py
# file name: type_cast_9.py
from type_cast_8 import DoSomethingWithB

print(DoSomethingWithB().do().b)

<filename>type_cast/type_cast_9.py
# file name: type_cast_9.py
from type_cast_8 import DoSomethingWithB

print(DoSomethingWithB().do().b)

# file name: type_cast_9.py